Added Group, Updated Project Models, and implemented auto-fetch for projects/groups.

This merge adds several new changes to lay the groundwork for adding a ProjectListView and ProjectDetailView.

1.) New Model: GLGroup (did not use Group as Groups are native to Django for user authentication.): 2.) Updated Project model to make easy admin creation: The only required field when adding a project to the database is the gitlab_id. All other fields can be left blank. When a project is saved, Django will automatically attempt to pull the project details from gitlab and save them to the project. It will also attempt to find a GLGroup with a gitlab_id matching the gitlab instance's project id (from gl.project.namespace['id']. If there is not a matching GLGroup in the database, Django will create one and assign the group details with a gl.groups.get query. 3.) A base ProjectListView has been created (...//projects) which currently displays a blank template and is assigned to the Project model.