[rbslack] Polish up the configuration page.
Review Request #6295 — Created Sept. 3, 2014 and submitted
This adds some additional instructions to the configuration page and
fixes up the labels and widths.It also makes the channel field optional, since by default,
notifications will go to the channel configured with the "Incoming
WebHook" integration.
Tested with and without a configured channel, and saw it go to the
right place.
Tool: PEP8 Style Checker Processed Files: rbslack/rbslack/extension.py rbslack/rbslack/forms.py Tool: Pyflakes Processed Files: rbslack/rbslack/extension.py rbslack/rbslack/forms.py