style: fix small refactor leftovers

mattermost_matchmaker/run.py

 #!/usr/bin/env python3
-
 import argparse
-
 import mattermost
-from coffee_bot.match_making import matching_in_channel
+from mattermost_matchmaker.matchmaking import matching_in_channel
 
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description="Make matches between channel members")

tests/test_lint.py

 from unittest import TestCase
 #pylint: disable=missing-class-docstring,missing-function-docstring
-import sys
 import pathlib
 from pylint import epylint