Unbeta Dashboards

Summary: Fixes T4980. I think we've fixed all the unusable stuff, and it doesn't make much sense to leave this in beta since installing dashboards on the homepage is functionally important in order to use the application.

Test Plan: Observed no beta star on launcher view.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T4980

Differential Revision: https://secure.phabricator.com/D9671