Fix brittle tests.

`#debug?` depends on whether or not the debugger is loaded. The tests for
it were brittle and could start to fail if you were running the specs with
the debugger loaded.
Don't use coveralls when running each spec individually.

On the coveralls UI I'm seeing the same file listed many times.  I think it's because we run all the specs together and then run each individually and the
multiple test runs confuses it.
Disable coveralls from the cukes.

That last commit improved the coveralls percent but the results
are still a bit odd. In our cukes, the rspec code is only run in a
separate process started by aruba using the rspec command. I don't
think that our cukes provide useful info about the coverage percent
due to the separate processes.
Make coveralls ignore spec and tmp files.

We really only care about the coverage of our lib files.
Merge pull request #935 from rspec/fix_coveralls

Fix coveralls and a brittle test