Fix test cases in tests.unit.test_service
Fix test cases in tests.unit.test_service

Be patient in test_service while waiting service to be spawned or killed,
because:
    * Service spawning has a limit of one process a second.
    * A test server in the cloud might have limited resources, the time there
      might be several times slower.

Change-Id: Idab1d1158ecc7564d0b1f9cdd32496496ff5b3f8

JioCloud/oslo-incubator,JioCloud/oslo-incubator,JioCloud/oslo-incubator