Somewhere here it would be great to mention that socorro does not exclusively contain **unit** tests. 
Usually pure unit tests don't require any database connections but we have plenty of tests that do require a real database. 

There's some confusion in the eco system of the meaning of "integration tests" and "functional tests" and "end-to-end tests". 
To **me**, integration tests are tests that are run by Nose, is pure python but actually uses a real database.