Fix compute test_agents tests

Trying to keep the same methods for all tests classes steps .
Evrey testcase creates an agent , it is deleted in addCleanup.

Remove setUp(self) , Use resource_setup() for class
Change  _param_helper to @staticmethod
Remove testcases tearDown, there is addCleanup for each testcase

Change-Id: Idc46d46eb5b154aae024b868da2c97b3c6bbdcdd
1 file changed