[BTR-38] [BB-3269] Add openassessmnet url to CMS

This change helps to check the preview of fileupload in
openassessment xblock in studio.

Signed-off-by: Farhaan Bukhsh <farhaan@opencraft.com>

cms/urls.py

@@ -198,6 +198,10 @@ JS_INFO_DICT = {
     'packages': ('openassessment',),
 }
 
+urlpatterns += [
+    url(r'^openassessment/fileupload/', include('openassessment.fileupload.urls')),
+]
+
 if settings.FEATURES.get('ENABLE_CONTENT_LIBRARIES'):
     urlpatterns += [
         url(r'^library/{}?$'.format(LIBRARY_KEY_PATTERN),