End no-color's description with period punctuation
It would be nice, if like description of other options, "--no-color"'s
description also ends with a period.
@@ -187,7 +187,7 @@ no_color = partial(
dest='no_color',
action='store_true',
default=False,
- help="Suppress colored output",
+ help="Suppress colored output.",
) # type: Callable[..., Option]
version = partial(
