Explicitly set the test database name

Currently we are relying on Django’s internal test setup to add a `test_` prefix
to the default database name. This works fine most of the time but it’s better
to be explicit.

koku/koku/database.py

@@ -116,6 +116,9 @@ def config():
         "HOST": CONFIGURATOR.get_database_host(),
         "PORT": CONFIGURATOR.get_database_port(),
         "OPTIONS": {"application_name": ENVIRONMENT.get_value("APPLICATION_NAME", default="koku")},
+        "TEST": {
+            "NAME": f"test_{name}",
+        },
     }
 
     database_cert = CONFIGURATOR.get_database_ca()