Currently one test is failing on jre11, possibly because of a Groovy Bug : https://issues.apache.org/jira/browse/GROOVY-8871

gstorm.GstormDataTypesTest > initializationError FAILED
java.lang.IllegalAccessError at GstormDataTypesTest.groovy:-1
73 tests completed, 1 failed

Try to update to groovy 2.5.4 once released to see if that fixes the issue.