Really don't show location hours when they're blank.

The microformats2 asplodes when there is an empty p-hours tag. The hours
field ends up being a blank string if it's not specified, so the
existing conditional didn't really keep it from showing up.
Specs for attributes g5_foundation_client relies on.

I decided to only spec the fields I'm actually using for the API gem.
These specs establish a contract between those two, and I don't want to
lock this side's markup down for no reason.
Merge pull request #32 from G5/location-page-fixin

Location page fixes.