pywatchman: add test_suite argument to setup.py
pywatchman: add test_suite argument to setup.py

This allows running `python setup.py test` to run the full pywatchman test
suite.

facebook/watchman,wez/watchman,kwlzn/watchman,dhruvsinghal/watchman,facebook/watchman,dhruvsinghal/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,wez/watchman,kwlzn/watchman,facebook/watchman,dhruvsinghal/watchman,wez/watchman,nodakai/watchman,kwlzn/watchman,wez/watchman,nodakai/watchman,kwlzn/watchman,kwlzn/watchman,facebook/watchman,facebook/watchman,facebook/watchman,dhruvsinghal/watchman,wez/watchman,kwlzn/watchman,wez/watchman,facebook/watchman,kwlzn/watchman,dhruvsinghal/watchman,dhruvsinghal/watchman,wez/watchman,dhruvsinghal/watchman,wez/watchman,wez/watchman,nodakai/watchman,nodakai/watchman,dhruvsinghal/watchman