Added neo4j/tx tests to travis Gremlin Server build
Added neo4j/tx tests to travis Gremlin Server build

These tests will make builds take a bit longer but they aren't run frequently enough especially while making server/driver changes. They shouldn't extended testing so long the tests timeout so let's try this config for a while and see what the effect is. CTR

apache/tinkerpop,apache/incubator-tinkerpop,apache/tinkerpop,apache/tinkerpop,apache/incubator-tinkerpop,apache/tinkerpop,apache/tinkerpop,apache/tinkerpop,apache/tinkerpop,apache/incubator-tinkerpop