Merge pull request #7710 from cpennington/relax-context-contract

Fix contract on context argument

common/djangoapps/xmodule_modifiers.py

@@ -196,7 +196,7 @@ def grade_histogram(module_id):
     return grades
 
 
-@contract(user=User, has_instructor_access=bool, block=XBlock, view=basestring, frag=Fragment, context=dict)
+@contract(user=User, has_instructor_access=bool, block=XBlock, view=basestring, frag=Fragment, context="dict|None")
 def add_staff_markup(user, has_instructor_access, block, view, frag, context):  # pylint: disable=unused-argument
     """
     Updates the supplied module with a new get_html function that wraps