chore(package): update eslint to version 6.3.0

Closes #9

Author: greenkeeper[bot]

package.json

@@ -38,7 +38,7 @@
     "babel-cli": "^6.26.0",
     "chai": "^4.2.0",
     "coveralls": "^3.0.2",
-    "eslint": "^5.11.1",
+    "eslint": "^6.3.0",
     "eslint-config-airbnb": "^17.1.0",
     "eslint-config-airbnb-base": "^13.1.0",
     "eslint-plugin-import": "^2.7.0",