fix bug 965590 - unify socorro to a single virtualenv

Why do you need these? 
I don't like the idea of mixing development requirements with real run-time requirements. 

crontabber solved this by having [two](https://github.com/mozilla/crontabber/blob/master/requirements.txt) [files](https://github.com/mozilla/crontabber/blob/master/test-requirements.txt)