blacked

black, but with single quotes

What's wrong with other 'single-quoted' black options:

• brunette: uses monkey patching that basically doesn't work when running against multiple files odwyersoftware/brunette#5
• axblack: forked from black a while ago, inconsistent with current black versions axiros/axblack#7

ToDo:

• add tests:
  • Both blacked -S and black -S must produce same results
  • blacked run against code formatted with black must change only quotes and vice-versa
  • blacked must adopt any currently installed black version
  • Tests must include running blacked against multiple files to assure multiprocessing works as expected
  • Tests must include latest or all black versions
• add support for config.cfg
• add support for blackd