Try to configure Travis to build with JDK 9

wilkinsona · snicoll · commit d9f58b206869 · 2017-08-17T14:13:13.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,11 +1,13 @@
 language: java
 jdk:
-  - oraclejdk8
+  - oraclejdk9
 services:
   - mongodb
   - redis
   - cassandra
 sudo: required
+dist: trusty
+group: edge
 cache:
   directories:
     - $HOME/.m2
