Move people box on project pages

Summary: This removes the people box and adds a members property list item it's place. We may want some show/hide/see all if a project has more than n members, but these seems more reasonable than previous layout.

Test Plan: Tested a project with and without members, grepped for removed CSS, and tested mobile and desktop layouts.

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7870