+ I use the library django-social-auth to login to facebook and google. You can change the latest version.
We do not know how to have git+https://github.com/edx/django-social-auth.git

+ After clone source edx/edx-platform, edit file requirements/edx/github.txt and add line 
-e git+https://github.com/omab/django-social-auth.git@v0.7.12#egg=django-social-auth
Run scripts/create-dev-env.sh set up  a development environment.