Adds RVM .ruby-version
Adds track number to Track.

Track new/edit forms include track number field. Track lists on
band and album show pages will order tracks by their track number.

Track's new and index routes now nested under Album route.
Updates database seeds.rb to account for track numbers.
Checks for admin status on destroy actions

Also fixes before_filter typo for detstroy action.
Adds activate/deactivate put actions
Adds User show/index actions