Black formatting leads to python2 syntax error

[dummyindex]

Since cellProfiler stable version still uses python2.7, I installed Cellprofiler and centrosome with pip2.

Some commits change add "," to "**kwargs" lines, leading to syntax errors.
Example:
Set.py: line 84, need to remove comma to avoid syntax error in python2 syntax
threshold.py: python2.7/site-packages/centrosome/threshold.py", line 82, **kwargs

[dummyindex]

There is a pull request awaiting for merge to fix this issue. #98