Fix #167 - Enable cmd+enter on Mac to submit form

app/assets/javascripts/components/features/compose/components/compose_form.jsx

@@ -95,7 +95,7 @@ const ComposeForm = React.createClass({
   },
 
   handleKeyUp (e) {
-    if (e.keyCode === 13 && e.ctrlKey) {
+    if (e.keyCode === 13 && (e.ctrlKey || (e.metaKey && e.metaKey === '⌘-'))) {
       this.props.onSubmit();
     }
   },