Check if we can run the tests without fiddling with the request layers

[ale-rt]

The answer is yes, they do:

ale@avo:~/Code/plone/tests/osha-oira$ ./bin/test -t OiRARiskTests                                                                                                                                                                                                                                                                                                                            
...
  Ran 2 tests with 0 failures, 0 errors, 0 skipped in 10.657 seconds.
Tearing down left over layers:
  Tear down osha.oira.testing.osha.oira:Integration in 0.000 seconds.
  Tear down osha.oira.testing.OiRAFixture in 0.002 seconds.
  Tear down plone.app.testing.layers.PloneFixture in 0.017 seconds.
  Tear down plone.testing.zope.Startup in 0.002 seconds.
  Tear down plone.testing.zca.LayerCleanup in 0.001 seconds.