Use latest version of black (python-cmd2#1201)

Author: tleonhardt

examples/arg_decorators.py

@@ -49,7 +49,7 @@ def do_fsize(self, args: argparse.Namespace) -> None:
     @cmd2.with_argparser(pow_parser)
     def do_pow(self, args: argparse.Namespace) -> None:
         """Raise an integer to a small integer exponent, either positive or negative"""
-        self.poutput('{} ** {} == {}'.format(args.base, args.exponent, args.base ** args.exponent))
+        self.poutput('{} ** {} == {}'.format(args.base, args.exponent, args.base**args.exponent))
 
 
 if __name__ == '__main__':