ARTEMIS-2109: enable JDK11 + JDK14 builds in Travs CI, and fix before_cache config
ARTEMIS-2109: enable JDK11 + JDK14 builds in Travs CI, and fix before_cache config

jbertram/activemq-artemis,clebertsuconic/activemq-artemis,clebertsuconic/activemq-artemis,andytaylor/activemq-artemis,apache/activemq-artemis,andytaylor/activemq-artemis,tabish121/activemq-artemis,kjniemi/activemq-artemis,clebertsuconic/activemq-artemis,kjniemi/activemq-artemis,TomRoss/activemq-artemis,tabish121/activemq-artemis,jbertram/activemq-artemis,tabish121/activemq-artemis,jbertram/activemq-artemis,TomRoss/activemq-artemis,TomRoss/activemq-artemis,clebertsuconic/activemq-artemis,kjniemi/activemq-artemis,tabish121/activemq-artemis,TomRoss/activemq-artemis,kjniemi/activemq-artemis,graben/activemq-artemis,graben/activemq-artemis,apache/activemq-artemis,jbertram/activemq-artemis,apache/activemq-artemis,graben/activemq-artemis,andytaylor/activemq-artemis,andytaylor/activemq-artemis,graben/activemq-artemis,kjniemi/activemq-artemis,apache/activemq-artemis