chore(package): update eslint to version 6.2.2

Closes #19

Author: greenkeeper[bot]

package.json

@@ -66,7 +66,7 @@
     "conventional-changelog-cli": "^1.2.0",
     "coveralls": "^2.11.14",
     "cz-conventional-changelog": "^1.2.0",
-    "eslint": "^3.14.0",
+    "eslint": "^6.2.2",
     "eslint-plugin-ava": "^4.0.1",
     "fake-indexeddb": "^1.0.8",
     "fetch-mock": "^5.5.0",