Revert "Add JUnit testing for ConfigurationServiceImpl class."

Revert "Add JUnit testing for ConfigurationServiceImpl class."

This reverts commit eb362a3e296c10ad8ac7b5cb626cd2466f4d558b.

This is to stop regression introduced, where hit the following failure:

https://jenkins.opendaylight.org/releng/view/ovsdb/job/ovsdb-daily-full-integration/OVS_VERSION=1.9.0,jdk=openjdk7,nodes=dynamic_docker/23/consoleFull

apiTests(org.opendaylight.ovsdb.integrationtest.plugin.OvsdbPluginIT)
Tests run: 3, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 53.545 sec <<< FAILURE! - in org.opendaylight.ovsdb.integrationtest.plugin.OvsdbPluginIT
testInventoryListeners(org.opendaylight.ovsdb.integrationtest.plugin.OvsdbPluginIT)  Time elapsed: 10.368 sec  <<< ERROR!
java.lang.NullPointerException: null
	at org.mockito.internal.exceptions.stacktrace.StackTraceFilter.<clinit>(StackTraceFilter.java:21)
	at org.mockito.internal.exceptions.stacktrace.ConditionalStackTraceFilter.<init>(ConditionalStackTraceFilter.java:17)
	at org.mockito.exceptions.base.MockitoException.filterStackTrace(MockitoException.java:30)
	at org.mockito.exceptions.base.MockitoException.<init>(MockitoException.java:19)
	at org.mockito.exceptions.misusing.MockitoConfigurationException.<init>(MockitoConfigurationException.java:18)
	at org.mockito.internal.configuration.ClassPathLoader.loadImplementations(ClassPathLoader.java:145)
	at org.mockito.internal.configuration.ClassPathLoader.findPluginImplementation(ClassPathLoader.java:110)
	at org.mockito.internal.configuration.ClassPathLoader.findPlatformMockMaker(ClassPathLoader.java:106)
	at org.mockito.internal.configuration.ClassPathLoader.<clinit>(ClassPathLoader.java:59)
	at org.mockito.internal.util.MockUtil.<clinit>(MockUtil.java:21)
	at org.mockito.internal.MockitoCore.<init>(MockitoCore.java:40)
	at org.mockito.Mockito.<clinit>(Mockito.java:932)
	at org.opendaylight.ovsdb.integrationtest.plugin.OvsdbPluginIT.testInventoryListeners(OvsdbPluginIT.java:171)

Change-Id: I13d0c3193e297eb9b825bd657478955fc7876733
Signed-off-by: Flavio Fernandes <ffernand@redhat.com>