Add GitHub account to profile settings page
requested to merge karloxyz/gitlab-ce:feature/13401-add-github-account-to-profile-settings into master
For #13401 (moved) to work, a user must be able to link a GitHub
account to his/her GitLab account. This was done simply by adding a github column to the users table and displaying the necessary field in the profile settings page. I just copied how the Skype and Twitter fields were implemented.
