Make test computations explicit

This test is full of magic numbers, making it very difficult to fix when
the underlying code changes. There are some obvious errors, such as an
instance having a different memory_mb value than its flavor. This patch
attempts to sort these issues out, making it easier to work on the
resource tracker with confidence.

Change-Id: I4549f0d9b10a5ac65f169199b98b8975ef2a8cd3
Fix display of server group members

The previous code was failing to display the members of server
groups because it was filtering them all out.

Interestingly, the previous code passes the unit tests due to a
bug where we treat regex comparisons differently when using mysql
vs sqlite (tracked under bug 1298690).

Change-Id: I7be9c180f4284dd18cd02e510e77e3c1e3fc9925
Closes-bug: 1298494
Use one query instead of two for quota_usages

The second query was unnecessary and not using a proper index. It
seemed to be contributing to a deadlock issue as well.

Change-Id: I1031451b25140d71380c8149d3c83827eec0d4a9
Closes-Bug: #1308715
Co-Authored-by: Chris Behrens <cbehrens@codestud.com>
Merge "Make test computations explicit"
Merge "Use one query instead of two for quota_usages"
Merge "Fix display of server group members"