Upgrade to edx-auth-backends 0.5.2

requirements/base.txt

@@ -20,7 +20,7 @@ djangorestframework-xml==1.3.0
 django-rest-swagger[reST]==0.3.7
 drf-haystack==1.6.0rc1
 dry-rest-permissions==0.1.6
-edx-auth-backends==0.5.1
+edx-auth-backends==0.5.2
 edx-ccx-keys==0.2.0
 edx-django-release-util==0.1.0
 edx-drf-extensions==1.1.1
@@ -32,6 +32,3 @@ pillow==3.3.0
 pycountry==1.20
 python-dateutil==2.5.3
 pytz==2016.4
-
-# ECOM-5232: This custom version includes a migration fix that prevents us from having to fake migrations.
-git+https://github.com/clintonb/python-social-auth.git@edx-migration-fix#python-social-auth==0.2.21.edx