add --parent-diff-filename option to rbt post
Review Request #9783 — Created March 15, 2018 and updated
rbt posthas the ability to create a review with a "parent" diff, but there's no option to provide one. This patch adds it.
I have successfully created a review in our company's RB installation using an
rbtwith this patch.
E501 line too long (85 > 79 characters)