fix(travis): build pass, adding openjdk11 matrix verification

Author: vongosling

.travis.yml

@@ -1,3 +1,5 @@
+dist: trusty
+
 language: java
 
 addons:
@@ -17,8 +19,10 @@ install:
 jdk:
 - oraclejdk8
 - oraclejdk9
+- oraclejdk11
 - openjdk7
-- openjdk6
+- openjdk8
+
 
 script: mvn install
 env: