Fix Logger tests,test user provided namespaces more
Fix Logger tests,test user provided namespaces more

Adds tests that test the use of ``user_name`` in `Logger.add` and
`Logger.remove`.

joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue