Add os-collect-config to requirements

The test that uses os-collect-config, ZaqarSignalTransportTest, is
staying in heat-tempest-plugin and being removed from
heat_integrationtests in the Heat tree. Add it to requirements here so
we can drop it from test-requirements there.

Change-Id: Ieadd9ecac0df4e921f96282f4f807df7ff81c26f
1 file changed