Fix more lint errors

Signed-off-by: Aaron Raimist <aaron@raim.ist>

src/components/views/rooms/RoomDropTarget.js

@@ -16,7 +16,7 @@ limitations under the License.
 
 'use strict';
 
-var React = require('react');
+const React = require('react');
 
 module.exports = React.createClass({
     displayName: 'RoomDropTarget',
@@ -31,5 +31,5 @@ module.exports = React.createClass({
                 </div>
             </div>
         );
-    }
+    },
 });