Implemented delete. Delete option now only available to bounty owner.
Added test for Brent to review
Better organize the new Bounty#destroy() tests.
Don't import SessionsHelper into the Bounty model tests.

This breaks the new Bounty model tests, but they aren't actually model
tests--they're testing the Bounty controller's destroy() method and are
meant to be placed in the Bounty controller tests, not the Bounty model
tests. They will be moved in a future commit.
Add a stub for a test to check that Bounty.destroy() does not work on accepted bounties.
Remove a stray tab.
Added the ability to check a bounties status and then used it to confirm a bounty is in a status in which it may be removed.
Removed testing lines.
Added tests for bounty.status
Added commented out test to the bounty controller, where CRUD actions must be tested.