Merge pull request #7246 from cguardia/patch-1

Add empty introspection rule for BlockTypeKeyField.

AUTHORS

@@ -199,3 +199,4 @@ Mat Moore <mat@mooresoftware.co.uk>
 Muzaffar Yousaf <muzaffar@edx.org>
 Sylvain <sylvain@openfun.fr>
 Mayank Jain <mjmayank@gmail.com>
+Carlos de la Guardia <cguardia@yahoo.com>

common/djangoapps/xmodule_django/models.py

@@ -179,3 +179,4 @@ class BlockTypeKeyField(OpaqueKeyField):
 add_introspection_rules([], [r"^xmodule_django\.models\.CourseKeyField"])
 add_introspection_rules([], [r"^xmodule_django\.models\.LocationKeyField"])
 add_introspection_rules([], [r"^xmodule_django\.models\.UsageKeyField"])
+add_introspection_rules([], [r"^xmodule_django\.models\.BlockTypeKeyField"])