chore(package): update eslint to version 6.2.2

Closes #15

Author: greenkeeper[bot]

package.json

@@ -13,7 +13,7 @@
     "babel-eslint": "^8.2.6",
     "css-loader": "^1.0.0",
     "cssnano": "^4.0.4",
-    "eslint": "^5.2.0",
+    "eslint": "^6.2.2",
     "eslint-config-prettier": "^2.9.0",
     "eslint-plugin-prettier": "^2.6.2",
     "html-webpack-plugin": "^3.2.0",