FC007: accept 'suggests' and 'recommends'

Chef supports the `suggests` and `recommends` as keywords for soft
dependencies. They are a NOOP and the semantics are a bit
[unclear](http://tickets.opscode.com/browse/CHEF-3870) but they're
[used](socrata-cookbooks/java@90ecd3db) for "most people don't need
this" dependencies, e.g. depending on the `windows` cookbook.

Fixes acrmp/foodcritic#159.