Consolidate the test suite

[g2p]

There are integration tests in .travis.yml (which also run the unit tests through setup.py for increased coverage), a test_activate.sh which is too rigid for pypy, the aforementioned unit tests, and a tox config file. The integration tests should be extracted to a separate script that tests activation as well.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Just add a comment if you want to keep it open. Thank you for your contributions.