Default Pholio mocks to "Open" on create

Summary: When you currently create a Pholio Mock, it's closed if you didn't notice the select. This hides the input.

Test Plan: Created a Pholio Mock, verified it was open

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9522