Travis build matrix:  add [openjdk11]
@@ -7,6 +7,7 @@ jdk:
- openjdk8
- openjdk9
- openjdk10
+- openjdk11
before_script:
- wget "https://github.com/nats-io/nats-server/releases/download/$nats_server_version/gnatsd-$nats_server_version-linux-amd64.zip"
-O tmp.zip
