try to fix travis build

Author: cowtowncoder

.travis.yml

@@ -2,8 +2,8 @@ language: java
 
 # Since Jackson 2.7, build requires jdk7, although module itself works on jdk6 still (for now)
 jdk:
-  - oraclejdk7
-  - oraclejdk8
+  - openjdk7
+  - openjdk8
 
 # Below this line is configuration for deploying to the Sonatype OSS repo
 # http://blog.xeiam.com/2013/05/configure-travis-ci-to-deploy-snapshots.html