Fix tests - ContainerUpgradeAndRollbackTest force clean and dosgi InvocationTest

I was seeing test failures - one without mvn clean, and the other having to do with asynchronous tests not giving enough time for results (on my machine anyhow) and addressed them with these two changes. One I did a force clean for integration tests, as they fail if you run tests a second time (without clean) due to existing fabric in itests/smoke/karaf/target/fabric8-karaf-1.1.0-SNAPSHOT/instances

Aug 31, 2014 8:14:37 AM org.jboss.arquillian.protocol.jmx.JMXMethodExecutor invoke
SEVERE: Failed: io.fabric8.itests.smoke.karaf.ContainerUpgradeAndRollbackTest.testContainerUpgradeAndRollback
io.fabric8.api.FabricException: java.util.concurrent.ExecutionException: io.fabric8.api.FabricException: Failed to create container.