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/prompt.js

@@ -1,12 +1,15 @@
 module.exports = {
   confirm_release: {
     options: {
-      questions: [{
-        config: 'confirm.release',
-        type: 'confirm',
-        message: 'Are you sure you want to overwrite/release version <%= package.version %> of elasticsearch-js',
-        default: false
-      }]
-    }
-  }
+      questions: [
+        {
+          config: 'confirm.release',
+          type: 'confirm',
+          message:
+            'Are you sure you want to overwrite/release version <%= package.version %> of elasticsearch-js',
+          default: false,
+        },
+      ],
+    },
+  },
 };