Added validations to user submissions
Fixes #83

This involves making a form object (Contribution)
I've also fixed up the routes to use standard resourceful routing.
Added feature spec for submitting a capstone with errors and resolving.
Remove unused self_deposit model/controller/views
Authorize contribute controller actions
removed app/views/contribute/metadata
Merge pull request #92 from curationexperts/validations

Added validations to user submissions