No such test method for python unittest

I am new to unittest so I am not sure why I am getting this error:

Traceback (most recent call last):
  File "filemerge_test.py", line 98, in <module>
    main(sys.argv)
  File "filemerge_test.py", line 92, in main
    filemerge_test.test_runner()
  File "filemerge_test.py", line 19, in test_runner
    self.addTest(TestFunctionality(self.log, self.options))
  File "/nfsdata/DSCluster/home/bli1/filemerge/tests/testcases.py", line 45, in __init__
    super(TestFunctionality, self).__init__()
  File "/usr/local/lib/python2.7/unittest/case.py", line 191, in __init__
    (self.__class__, methodName))
ValueError: no such test method in <class 'testcases.TestFunctionality'>: runTest

Full code is here: http://ift.tt/1Rpwb7A

I think it is because I am not running the tests correctly.

Here is a summary of how my testing is currently written:

from testcases import TestFunctionality

class FileMergerTest(unittest.TestSuite)
    def __init__(self, log, options):
        super(FileMergerTest, self).__init__()
        self.options = options
        self.log = log

    def test_runner(self):
        self.addTest(TestFunctionality(self.log, self.options))
        self.run()

def main()
    ...
    ...
    filemerge_test = FileMergerTest(log, options)
    filemerge_test.test_runner()


if __name__ == "__main__":
    main(sys.argv)

In my testcases.py where I imported TestFunctionality

class TestFunctionality(unittest.TestCase):
    def __init__(self, log, options):
        super(TestFunctionality, self).__init__()
        self.options = options
        self.log = log
        ...

    def test_outputs(self, test_type)
        ...
        ...

    def run(self):
        self.test_outputs("-d")
        self.test_outputs("-f")

I tried adding

if __name__ == '__main__':
    unittest.main()

At the end of my testcases.py file but I got the same error