Re-enable OpenJDK 7

Author: adamretter

.travis.yml

@@ -5,14 +5,10 @@ language: scala
 scala:
         - 2.11.6
 
-# before_install:
-#        - "sudo apt-get update"
-#        - "sudo apt-get install openjdk-6-jdk openjdk-7-jdk"
-
 script: "mvn test verify -Dmaven.javadoc.skip=true"
 
 jdk:
 #        - openjdk6
-#        - openjdk7
+        - openjdk7
         - oraclejdk7
         - oraclejdk8