fix(package): update eslint to version 5.15.0

Closes #135

Author: greenkeeper[bot]

package.json

@@ -13,7 +13,7 @@
     "babel-preset-latest": "^6.22.0",
     "babel-register": "^6.22.0",
     "commander": "^2.9.0",
-    "eslint": "^4.1.0",
+    "eslint": "^5.15.0",
     "eslint-plugin-babel": "^5.1.0",
     "moment": "^2.18.1",
     "moment-precise-range-plugin": "^1.2.1",