chore(package): update eslint to version 6.6.0

Closes #81

Author: greenkeeper[bot]

package.json

@@ -29,7 +29,7 @@
     "babel-jest": "^23.4.2",
     "babel-preset-minify": "^0.4.3",
     "codecov": "^3.0.4",
-    "eslint": "^4.19.1",
+    "eslint": "^6.6.0",
     "eslint-config-airbnb-base": "^13.0.0",
     "eslint-plugin-import": "^2.13.0",
     "husky": "^0.14.3",