implement pytest plugin support directly in docker-compose itself

[waynr]

A thought that occurs to me is that it might be a good idea to add pytest features directly to docker-compose itself. Advantages, assuming docker-compose maintainers would allow it, include the following:

• Improve visibility of these fixtures in the python and docker-compose communities, thereby making it more likely to get new features and bug fix support.
• Make it possible through test coverage in that project to prevent fixture breakage due to breaking upstream library api changes; users of this project may be put in the unfortunate position of wanting new docker-compose features but not being able to upgrade it in their projects' virtualenvs because newer versions of docker-compose may behavior here.

[AndreLouisCaron]

That sounds like a great idea, but, as I mentioned in #19, I'm not up to that task. If you put any effort into making that happen, please let me know and I will retire this project.