Whitelist Foodcritic rule FC017

Foodcritic 3.0.0 gives false positives for FC017[1], i.e.
"LWRP does not notify when updated". The "repository" provider has the
notification logic in helper methods so foodcritic gets fooled.

[1]: http://www.foodcritic.io/#FC017
Upgrade Foodcritic to 3.x

Drop guard-foodcritic for now as it depends on <3.0.