Added OpenJDK to TravisCI config.

Author: jdantonio

.travis.yml

@@ -1,26 +1,36 @@
 language: ruby
-
 rvm:
   - 2.2.0
   - 2.1.5
-  - 2.1.4
   - 2.0.0
   - 1.9.3
   - ruby-head
   - jruby-1.7.19
   - jruby-head
   - rbx-2
-
-jdk:
+jdk: # for JRuby only
+  - openjdk7
   - oraclejdk8
-
-sudo: false
-
-branches:
-  only:
-    - master
-
 matrix:
+  exclude:
+    - rvm: 2.2.0
+      jdk: openjdk7
+      jdk: oraclejdk8
+    - rvm: 2.1.5
+      jdk: openjdk7
+      jdk: oraclejdk8
+    - rvm: 2.0.0
+      jdk: openjdk7
+      jdk: oraclejdk8
+    - rvm: 1.9.3
+      jdk: openjdk7
+      jdk: oraclejdk8
+    - rvm: ruby-head
+      jdk: openjdk7
+      jdk: oraclejdk8
+    - rvm: rbx-2
+      jdk: openjdk7
+      jdk: oraclejdk8
   allow_failures:
     - rvm: ruby-head
     - rvm: jruby-head