Don't show empty attributes.
Summary: Some places we pass in empty strings and get hanging middots. Would prefer not have the middot, and let the developer decide if they should set a 'nothing here' state.
Test Plan: Checked Repositories with no lint messages.
Reviewers: epriestley, btrahan
Reviewed By: epriestley
CC: aran, Korvin
Differential Revision: https://secure.phabricator.com/D5920