Supply an User-Agent for Github according to: http://developer.github.com/changes/2013-01-31-user-agent-will-soon-be-mandatory/
Added method get_user_information() and get_user() for Foursquare provider
Merge pull request #8 from MathijsJH/master

Added methods to get user infomration for Foursquare and fixed Github API call according to API change.