Fail if coverage under threshold

[damienmac]

Many coverage tools will "fail" if below a configured threshold. This allows my build system to ensure nobody adds new code without also adding unit tests.

What would you think about adding this feature to deep-cover? When the final
"Overall: 2.61%" is less than "2.00%", for example, where 2.00 was on the command line or config file, then the return code would be non-zero.

Awesome coverage tool, keep up the great work!
-Damien

[marcandre]

Sounds like a cute feature, definitely.

Do you think you might be able to provide a PR for this?