temporarily disable test_no_attach_to_event_loop

temporarily disable test_no_attach_to_event_loop

this test currently causes the test suite to hang; it previously
was not actually running the worker thread
as the testing_engine() fixture
was rejecting the "transfer_staticpool" keyword argument.

as we seem to have a greenlet-related segfault in 3.10.0b2 I am
going to have to get the greenlet devs to run the test suite
so i want to get anything not totally smooth out of it for the
moment.

Change-Id: Ib453d0bc23ca013598bc80ff29e5da496771d5b1