gitignore
Updated linkedin social account

added the following info to linkedin social account:
get_profile_url
get_avatar_url
to_str
Add username blacklist in BaseSignupForm.
We could provide list of usernames that can't be used in settings,
under USERNAME_BLACKLIST.
Merge pull request #233 from arctelix/linkedin-name

Linkedin account update
Cleaning up 'next' redirect handling
Merge pull request #234 from kriwil/username-blacklist

Add username blacklist in BaseSignupForm.