diff --git a/package.json b/package.json
index 42749df..f50c763 100644
--- a/package.json
+++ b/package.json
@@ -92,7 +92,7 @@
     "eslint-plugin-flowtype": "^2.30.0",
     "eslint-watch": "^3.0.0",
     "flow-bin": "^0.97.0",
-    "flow-copy-source": "^1.2.1",
+    "flow-copy-source": "^2.0.0",
     "flow-watch": "^1.1.0",
     "husky": "^0.14.3",
     "istanbul": "^0.4.5",
diff --git a/yarn.lock b/yarn.lock
index b481b53..d36a2ce 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -382,6 +382,10 @@ ansi-regex@^3.0.0:
   version "3.0.0"
   resolved "https://registry.npmjs.org/ansi-regex/-/ansi-regex-3.0.0.tgz#ed0317c322064f79466c02966bddb605ab37d998"
 
+ansi-regex@^4.1.0:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-4.1.0.tgz#8b9f8f08cf1acb843756a839ca8c7e3168c51997"
+
 ansi-styles@^2.2.1:
   version "2.2.1"
   resolved "https://registry.npmjs.org/ansi-styles/-/ansi-styles-2.2.1.tgz#b432dd3358b634cf75e1e4664368240533c1ddbe"
@@ -1568,7 +1572,7 @@ check-error@^1.0.1:
   version "1.0.2"
   resolved "https://registry.npmjs.org/check-error/-/check-error-1.0.2.tgz#574d312edd88bb5dd8912e9286dd6c0aed4aac82"
 
-chokidar@^1.4.3, chokidar@^1.6.1, chokidar@^1.7.0:
+chokidar@^1.4.3, chokidar@^1.6.1:
   version "1.7.0"
   resolved "https://registry.npmjs.org/chokidar/-/chokidar-1.7.0.tgz#798e689778151c8076b4b360e5edd28cda2bb468"
   dependencies:
@@ -1649,14 +1653,6 @@ cliui@^2.1.0:
     right-align "^0.1.1"
     wordwrap "0.0.2"
 
-cliui@^3.2.0:
-  version "3.2.0"
-  resolved "https://registry.npmjs.org/cliui/-/cliui-3.2.0.tgz#120601537a916d29940f934da3b48d585a39213d"
-  dependencies:
-    string-width "^1.0.1"
-    strip-ansi "^3.0.1"
-    wrap-ansi "^2.0.0"
-
 cliui@^4.0.0:
   version "4.0.0"
   resolved "https://registry.npmjs.org/cliui/-/cliui-4.0.0.tgz#743d4650e05f36d1ed2575b59638d87322bfbbcc"
@@ -2134,6 +2130,10 @@ electron-to-chromium@^1.3.47:
   version "1.3.48"
   resolved "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.3.48.tgz#d3b0d8593814044e092ece2108fc3ac9aea4b900"
 
+emoji-regex@^7.0.1:
+  version "7.0.3"
+  resolved "https://registry.yarnpkg.com/emoji-regex/-/emoji-regex-7.0.3.tgz#933a04052860c85e83c122479c4748a8e4c72156"
+
 end-of-stream@^1.1.0:
   version "1.4.1"
   resolved "https://registry.yarnpkg.com/end-of-stream/-/end-of-stream-1.4.1.tgz#ed29634d19baba463b6ce6b80a37213eab71ec43"
@@ -2631,15 +2631,15 @@ flow-bin@^0.97.0:
   version "0.97.0"
   resolved "https://registry.yarnpkg.com/flow-bin/-/flow-bin-0.97.0.tgz#036ffcfc27503367a9d906ec9d843a0aa6f6bb83"
 
-flow-copy-source@^1.2.1:
-  version "1.2.1"
-  resolved "https://registry.npmjs.org/flow-copy-source/-/flow-copy-source-1.2.1.tgz#705c2fa8fb29a281118e1c4b66218dec24b745ec"
+flow-copy-source@^2.0.0:
+  version "2.0.3"
+  resolved "https://registry.yarnpkg.com/flow-copy-source/-/flow-copy-source-2.0.3.tgz#d4666b5bd556f8b3b80dc42d4dd7fb128f57c2d9"
   dependencies:
-    chokidar "^1.7.0"
-    fs-extra "^3.0.1"
+    chokidar "^2.0.0"
+    fs-extra "^7.0.0"
     glob "^7.0.0"
     kefir "^3.7.3"
-    yargs "^8.0.2"
+    yargs "^13.1.0"
 
 flow-watch@^1.1.0:
   version "1.1.1"
@@ -2711,17 +2711,17 @@ fs-exists-sync@^0.1.0:
   version "0.1.0"
   resolved "https://registry.npmjs.org/fs-exists-sync/-/fs-exists-sync-0.1.0.tgz#982d6893af918e72d08dec9e8673ff2b5a8d6add"
 
-fs-extra@^3.0.1:
-  version "3.0.1"
-  resolved "https://registry.npmjs.org/fs-extra/-/fs-extra-3.0.1.tgz#3794f378c58b342ea7dbbb23095109c4b3b62291"
+fs-extra@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.npmjs.org/fs-extra/-/fs-extra-5.0.0.tgz#414d0110cdd06705734d055652c5411260c31abd"
   dependencies:
     graceful-fs "^4.1.2"
-    jsonfile "^3.0.0"
+    jsonfile "^4.0.0"
     universalify "^0.1.0"
 
-fs-extra@^5.0.0:
-  version "5.0.0"
-  resolved "https://registry.npmjs.org/fs-extra/-/fs-extra-5.0.0.tgz#414d0110cdd06705734d055652c5411260c31abd"
+fs-extra@^7.0.0:
+  version "7.0.1"
+  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-7.0.1.tgz#4f189c44aa123b895f722804f55ea23eadc348e9"
   dependencies:
     graceful-fs "^4.1.2"
     jsonfile "^4.0.0"
@@ -2784,6 +2784,10 @@ get-caller-file@^1.0.1:
   version "1.0.2"
   resolved "https://registry.npmjs.org/get-caller-file/-/get-caller-file-1.0.2.tgz#f702e63127e7e231c160a80c1554acb70d5047e5"
 
+get-caller-file@^2.0.1:
+  version "2.0.5"
+  resolved "https://registry.yarnpkg.com/get-caller-file/-/get-caller-file-2.0.5.tgz#4f94412a82db32f36e3b0b9741f8a97feb031f7e"
+
 get-func-name@^2.0.0:
   version "2.0.0"
   resolved "https://registry.npmjs.org/get-func-name/-/get-func-name-2.0.0.tgz#ead774abee72e20409433a066366023dd6887a41"
@@ -3813,12 +3817,6 @@ json5@^0.5.1:
   version "0.5.1"
   resolved "https://registry.npmjs.org/json5/-/json5-0.5.1.tgz#1eade7acc012034ad84e2396767ead9fa5495821"
 
-jsonfile@^3.0.0:
-  version "3.0.1"
-  resolved "https://registry.npmjs.org/jsonfile/-/jsonfile-3.0.1.tgz#a5ecc6f65f53f662c4415c7675a0331d0992ec66"
-  optionalDependencies:
-    graceful-fs "^4.1.6"
-
 jsonfile@^4.0.0:
   version "4.0.0"
   resolved "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz#8771aae0799b64076b76640fca058f9c10e33ecb"
@@ -3931,15 +3929,6 @@ load-json-file@^1.0.0:
     pinkie-promise "^2.0.0"
     strip-bom "^2.0.0"
 
-load-json-file@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.npmjs.org/load-json-file/-/load-json-file-2.0.0.tgz#7947e42149af80d696cbf797bcaabcfe1fe29ca8"
-  dependencies:
-    graceful-fs "^4.1.2"
-    parse-json "^2.2.0"
-    pify "^2.0.0"
-    strip-bom "^3.0.0"
-
 load-json-file@^4.0.0:
   version "4.0.0"
   resolved "https://registry.npmjs.org/load-json-file/-/load-json-file-4.0.0.tgz#2f5f45ab91e33216234fd53adab668eb4ec0993b"
@@ -4648,7 +4637,7 @@ os-locale@^2.0.0:
     lcid "^1.0.0"
     mem "^1.1.0"
 
-os-locale@^3.0.0:
+os-locale@^3.0.0, os-locale@^3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/os-locale/-/os-locale-3.1.0.tgz#a802a6ee17f24c10483ab9935719cef4ed16bf1a"
   dependencies:
@@ -4837,12 +4826,6 @@ path-type@^1.0.0:
     pify "^2.0.0"
     pinkie-promise "^2.0.0"
 
-path-type@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.npmjs.org/path-type/-/path-type-2.0.0.tgz#f012ccb8415b7096fc2daa1054c3d72389594c73"
-  dependencies:
-    pify "^2.0.0"
-
 path-type@^3.0.0:
   version "3.0.0"
   resolved "https://registry.npmjs.org/path-type/-/path-type-3.0.0.tgz#cef31dc8e0a1a3bb0d105c0cd97cf3bf47f4e36f"
@@ -5001,13 +4984,6 @@ read-pkg-up@^1.0.1:
     find-up "^1.0.0"
     read-pkg "^1.0.0"
 
-read-pkg-up@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.npmjs.org/read-pkg-up/-/read-pkg-up-2.0.0.tgz#6b72a8048984e0c41e79510fd5e9fa99b3b549be"
-  dependencies:
-    find-up "^2.0.0"
-    read-pkg "^2.0.0"
-
 read-pkg-up@^3.0.0:
   version "3.0.0"
   resolved "https://registry.npmjs.org/read-pkg-up/-/read-pkg-up-3.0.0.tgz#3ed496685dba0f8fe118d0691dc51f4a1ff96f07"
@@ -5023,14 +4999,6 @@ read-pkg@^1.0.0:
     normalize-package-data "^2.3.2"
     path-type "^1.0.0"
 
-read-pkg@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.npmjs.org/read-pkg/-/read-pkg-2.0.0.tgz#8ef1c0623c6a6db0dc6713c4bfac46332b2368f8"
-  dependencies:
-    load-json-file "^2.0.0"
-    normalize-package-data "^2.3.2"
-    path-type "^2.0.0"
-
 read-pkg@^3.0.0:
   version "3.0.0"
   resolved "https://registry.npmjs.org/read-pkg/-/read-pkg-3.0.0.tgz#9cbc686978fee65d16c00e2b19c237fcf6e38389"
@@ -5240,6 +5208,10 @@ require-main-filename@^1.0.1:
   version "1.0.1"
   resolved "https://registry.npmjs.org/require-main-filename/-/require-main-filename-1.0.1.tgz#97f717b69d48784f5f526a6c5aa8ffdda055a4d1"
 
+require-main-filename@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/require-main-filename/-/require-main-filename-2.0.0.tgz#d0b329ecc7cc0f61649f62215be69af54aa8989b"
+
 require-package-name@^2.0.1:
   version "2.0.1"
   resolved "https://registry.npmjs.org/require-package-name/-/require-package-name-2.0.1.tgz#c11e97276b65b8e2923f75dabf5fb2ef0c3841b9"
@@ -5690,6 +5662,14 @@ string-width@^1.0.1, string-width@^1.0.2:
     is-fullwidth-code-point "^2.0.0"
     strip-ansi "^4.0.0"
 
+string-width@^3.0.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/string-width/-/string-width-3.1.0.tgz#22767be21b62af1081574306f69ac51b62203961"
+  dependencies:
+    emoji-regex "^7.0.1"
+    is-fullwidth-code-point "^2.0.0"
+    strip-ansi "^5.1.0"
+
 string_decoder@~1.0.3:
   version "1.0.3"
   resolved "https://registry.npmjs.org/string_decoder/-/string_decoder-1.0.3.tgz#0fc67d7c141825de94282dd536bec6b9bce860ab"
@@ -5712,6 +5692,12 @@ strip-ansi@^4.0.0:
   dependencies:
     ansi-regex "^3.0.0"
 
+strip-ansi@^5.1.0:
+  version "5.2.0"
+  resolved "https://registry.yarnpkg.com/strip-ansi/-/strip-ansi-5.2.0.tgz#8c9a536feb6afc962bdfa5b104a5091c1ad9c0ae"
+  dependencies:
+    ansi-regex "^4.1.0"
+
 strip-bom-buffer@^0.1.1:
   version "0.1.1"
   resolved "https://registry.npmjs.org/strip-bom-buffer/-/strip-bom-buffer-0.1.1.tgz#ca3ddc4919c13f9fddf30b1dff100a9835248b4d"
@@ -6255,7 +6241,7 @@ y18n@^3.2.1:
   version "3.2.1"
   resolved "https://registry.npmjs.org/y18n/-/y18n-3.2.1.tgz#6d15fba884c08679c0d77e88e7759e811e07fa41"
 
-"y18n@^3.2.1 || ^4.0.0":
+"y18n@^3.2.1 || ^4.0.0", y18n@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/y18n/-/y18n-4.0.0.tgz#95ef94f85ecc81d007c264e190a120f0a3c8566b"
 
@@ -6270,11 +6256,12 @@ yargs-parser@11.1.1, yargs-parser@^11.1.1:
     camelcase "^5.0.0"
     decamelize "^1.2.0"
 
-yargs-parser@^7.0.0:
-  version "7.0.0"
-  resolved "https://registry.npmjs.org/yargs-parser/-/yargs-parser-7.0.0.tgz#8d0ac42f16ea55debd332caf4c4038b3e3f5dfd9"
+yargs-parser@^13.0.0:
+  version "13.0.0"
+  resolved "https://registry.yarnpkg.com/yargs-parser/-/yargs-parser-13.0.0.tgz#3fc44f3e76a8bdb1cc3602e860108602e5ccde8b"
   dependencies:
-    camelcase "^4.1.0"
+    camelcase "^5.0.0"
+    decamelize "^1.2.0"
 
 yargs-parser@^8.0.0, yargs-parser@^8.1.0:
   version "8.1.0"
@@ -6347,23 +6334,21 @@ yargs@^11.0.0:
     y18n "^3.2.1"
     yargs-parser "^9.0.2"
 
-yargs@^8.0.2:
-  version "8.0.2"
-  resolved "https://registry.npmjs.org/yargs/-/yargs-8.0.2.tgz#6299a9055b1cefc969ff7e79c1d918dceb22c360"
+yargs@^13.1.0:
+  version "13.2.2"
+  resolved "https://registry.yarnpkg.com/yargs/-/yargs-13.2.2.tgz#0c101f580ae95cea7f39d927e7770e3fdc97f993"
   dependencies:
-    camelcase "^4.1.0"
-    cliui "^3.2.0"
-    decamelize "^1.1.1"
-    get-caller-file "^1.0.1"
-    os-locale "^2.0.0"
-    read-pkg-up "^2.0.0"
+    cliui "^4.0.0"
+    find-up "^3.0.0"
+    get-caller-file "^2.0.1"
+    os-locale "^3.1.0"
     require-directory "^2.1.1"
-    require-main-filename "^1.0.1"
+    require-main-filename "^2.0.0"
     set-blocking "^2.0.0"
-    string-width "^2.0.0"
+    string-width "^3.0.0"
     which-module "^2.0.0"
-    y18n "^3.2.1"
-    yargs-parser "^7.0.0"
+    y18n "^4.0.0"
+    yargs-parser "^13.0.0"
 
 yargs@~3.10.0:
   version "3.10.0"