Add a couples of test to the user test file.

Just playing a little bit with minitest.
Cleanup the routes.

I hate the comments in source/config files. They just explain thing
that can be found on the respective documentation page, so to hell with
them!
Bugfix a devise view.

I really don't know why that dash was there. In any case, now is gone.
Removes the registerable module from the user model.

Users should not be able to register. It's really not needed on this
application.
Add validations for the email and name attributes.

I guess the email validation is not needed (Because of devise)...
Add rails_admin configuration for this model.

Now, on the edit thingie we only show the only fields that should be
edited.
Add name, email and admin user tests.
Create and apply a migration to add name and admn attributes to the user model.

I mean, a user needs a name, and we need a way to know who is an admin,
don't we?