Creating header package and dropdown component

Packages/ohif-core/client/ui/index.js

@@ -4,6 +4,7 @@ import './dialog/display.js';
 import './dialog/spatial.js';
 import './dialog/unsavedChangesDialog.js';
 import './draggable/draggable.js';
+import './dropdown/dropdown.js';
 import './dropdown/form.js';
 import './resizable/resizable.js';
 import './unsavedChanges/unsavedChanges.js';