Get some level of meaningful status information into Harbormaster buildable list

Summary: Ref T1049. Nothing fancy, but shows red for fail/error and green for pass. See discussion in D7502.

Test Plan: {F78839}

Reviewers: hach-que, btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1049

Differential Revision: https://secure.phabricator.com/D7512