I have upgraded my Community version of PyCharm to 2016.3.2, and I'm not positive it was this exact version, but when I went to run files that had unittests in them, only some of them are recognized as UnitTests that I can right click and run.
I have looked to make sure that my classes implement unittest.TestCase
class clWorkflowWebClientTest(unittest.TestCase):
all of my tests begin with test_blahblah()
If I go into Edit Configurations and add one manually, I can right click and run it from the project tree, and it runs as a UnitTest. But I don't get the "Run UnitTests in Blah' dialog when I right click  the file.
This turned out to be an issue I caused myself. we had added a folder called 'UnitTest' and introducing this to the path caused issues with PyCharm knowing what was a true UnitTest file.
I still don't know exactly what caused some files to work, but there appears to be one method in those files that did work that was probably being imported from another file that had the proper pathing.
Did something Change with Pycharm 2016.3.2 - UnitTests no longer auto discovered