Use standard and prettier (#10)

* switch from custom eslint config to standard + prettier

* fix new standard eslint violations

* add editorconfig file

* auto-fix all other violations

* update lint yarn script

* remove jshint comment

grunt/config/webpack.js

@@ -3,5 +3,5 @@ module.exports = {
     require('../../webpack_config/browser'),
     require('../../webpack_config/angular'),
     require('../../webpack_config/jquery'),
-  ]
-}
+  ],
+};