Basic Khan Academy support
Fix readme
Fix backend name formatting
Struggling with Khan Academy again...

Conflicts:
	social/backends/khanacademy.py
Khan Academy oauth support now fully working
Fixed docs
Changed test name
Merge branch 'khan-academy-backend' of github.com:aniav/python-social-auth into aniav-khan-academy-backend
Quick khan academy docs
Merge branch 'aniav-khan-academy-backend'