Make JavaUtilsTest a bit more resilient.

One millisecond won't work on a busy system.
Add missing taskId to hashCode, equals and toString.
Merge pull request #276 from hgschmie/task-history-update-fix

Add missing taskId to hashCode, equals and toString.
Merge pull request #275 from hgschmie/java-utils-test-fix

Make JavaUtilsTest a bit more resilient.
sleep longer on this test too
don't run persister when database isn't configured
test out 2.18-SNAPSHOT for surefire

hopefully, this resolves travis hangings.
add surefire snapshot repo