Use alternative parse_options signature.

Flake8 has two choices here, first it tries
parse_options(optmanager, options, extra_args)
and if that fails with a TypeError, does
parse_options(options)

If parse_options fails, we get a cleaner single
exception if we use the first form - easier for
debugging.

flake8_black.py

@@ -138,7 +138,7 @@ def add_options(cls, parser):
         )
 
     @classmethod
-    def parse_options(cls, options):
+    def parse_options(cls, optmanager, options, extra_args):
         """Adding black-config option."""
         # We have one and only one flake8 plugin configuration
         if options.black_config is None: