Bypass running specs as if they were pending with Ctrl + T

This pull request implements a simple feature idea I would love to see in rspec:

Sometimes I have individual specs that hang or take forever. This commit allows users to bypass a long running specs by hitting `Ctrl + t` and sending the `INFO` interrupt signal. Currently I am just marking them as _pending_ but down the road you might consider adding more comprehensive reporting. Let me know what you think.