Workflow 2 mvp-module-library

[lhannest]

I published the mvp-module-library to PyPI, and you can see that in Workflow2/requirements.txt it's now installing it from PyPI. So we no longer need the git submodule, and we no longer need to worry about people forgetting to add the --recursive flag when cloning this translator-workflows repo.

I haven't deleted the git submodule yet because I don't want to mess anyone up for today's Workflow2 hackathon. But eventually it should be deleted, and any other workflow that uses mvp-module-library should install from PyPI as well.