buy title #39
issue #33: added django-social-auth to requirements and made required changes in emergent/settings.py and emergent/urls.py
issue #33: created login page with info about GitHub as only way to login
Merge remote-tracking branch 'remotes/upstream/master' into issue-33-github-login
issue #33: removed registration and all mentions of registration.
Merge remote-tracking branch 'upstream/master' into issue-33-github-login

Conflicts:
	emergent/settings.py
Merge remote-tracking branch 'remotes/upstream/rpg_ui' into issue-33-github-login

Conflicts:
	emergent/urls.py
Merge pull request #47 from trilliput/issue-33-github-login

fix #33 github login
merge with github auth #39
merge with github auth #39