Return a 403 if a view class's is_accessible returns false.
is_accessible says: Override this method to add permission checks.
This means that it should return forbidden since the item exists but you
are not allowed to see it
Merge pull request #320 from Trii/master-forbidden-on-not-accessible

Return a 403 if a view class's is_accessible() returns false.
Fix test that I missed
Merge pull request #322 from Trii/master-forbidden-on-not-accessible

I didn't think to check the tests . . . sorry!
Merge pull request #2 from mrjoes/master

Merge from upstream