Change "Create a comment..." to "Add a comment..."

web/react/components/create_comment.jsx

@@ -145,7 +145,7 @@ module.exports = React.createClass({
                             onUserInput={this.handleUserInput}
                             onKeyPress={this.commentMsgKeyPress}
                             messageText={this.state.messageText}
-                            createMessage="Create a comment..."
+                            createMessage="Add a comment..."
                             initialText=""
                             id="reply_textbox"
                             ref="textbox" />