QPIDJMS-333: update test dep to activemq-5.15.1
QPIDJMS-333: update test dep to activemq-5.15.1

apache/qpid-jms,gemmellr/qpid-jms,gemmellr/qpid-jms,tabish121/qpid-jms,apache/qpid-jms,tabish121/qpid-jms