Merge pull request #305 from zvezdan/fix-travis-checks

Switch to openjdk for Travis checks.

Author: zvezdan

.travis.yml

@@ -1,7 +1,7 @@
 language: java
 
 jdk:
-  - oraclejdk8
+  - openjdk8
 
 before_cache:
   - rm -f  $HOME/.gradle/caches/modules-2/modules-2.lock