TransactionTestCase causes tests to run with AUTOCOMMIT.

[Gavin Panella]

Using TransactionTestCase means that you get Django's default
transaction management, which is defined in the DATABASES stanza in
Django's settings. The default is `AUTOCOMMIT: True`, but this is not
how we expect MAAS to run, ever. However, setting `AUTOCOMMIT: False`
means I can't even start the test suite:

  $ bin/test.maas
  nosetests --exclude=provisioningserver --exclude=maastesting
    --exclude=maascli --logging-level=INFO --verbosity=1
  Creating test database for alias 'default'...
  Got an error creating the test database: CREATE DATABASE cannot run
    inside a transaction block

  Destroying old test database 'default'...
  Got an error recreating the test database: current transaction is
    aborted, commands ignored until end of transaction block

[Andres Rodriguez (andreserl)]

Dear user,

This is an automated message.

We believe this bug report is no longer an issue in the latest version of MAAS. For such reason, we are making this issue as Won't Fix. If you believe this issue is still present in the latest version of MAAS, please re-open this bug report.