Add wiki collaboration feature.

Add seeds file.

Fix for when no user is logged_in.

Failing spec for add_collaborators feature.

Fix for add_private_wikis feature.

Show shared wikis to collaborators. Broken: Non-logged in users cannot view wikis.

Add add_collaborators feature now working with passing tests.

Delete file.
Merge pull request #13 from coloradobum/add_collaborators

Add wiki collaboration feature.