Replace usage of unittest.TestCase with tests.utils.TestCase

test modules
tests.v1.test_security_services
tests.v1.test_services
tests.v1.test_share_networks
tests.v1.test_share_servers

inherit unittest.TestCase, but all test classes
should inherit tests.utils.TestCase

Change-Id: Ibac0b301cd74c32b4250105f00b0bb616639fbb3