Do not show onClicked warning if @type is "submit"

Author: tcjr

addon/components/es-button.js

@@ -12,8 +12,10 @@ export default class EsButtonComponent extends Component {
 
 
     if(!this.args.onClicked) {
-      // eslint-disable-next-line no-console
-      console.warn(new Error('Button created with no onClicked'));
+      if (this.args.type !== 'submit') {
+        // eslint-disable-next-line no-console
+        console.warn(new Error('Button created with no onClicked'));
+      }
     } else {
       this._onClicked = this.args.onClicked;
     }