`syncdb` subcommand was deprecated in django 1.7
and subsequently removed in 1.9.

Use `subprocess.check_call()` so we catch errors.

Add `shared-db` relation and enable debug logging in deployment
used in functional test.  Add functional test that authenticates
through the dashboard.

Update unit tests.

Change-Id: I567461e57ec431fc470d7a2a31d3f16e9dc50e8b
Closes-Bug: #1777358