Use oraclejdk8

openjdk8 is not supported by travis yet
diff --git a/.travis.yml b/.travis.yml
index 9b16d57..c0f28cf 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,2 +1,2 @@
 language: java
-jdk: openjdk8
+jdk: oraclejdk8