Drop Java 6 build since Java 7 is the requirement.
diff --git a/.travis.yml b/.travis.yml
index dd12baf..bc619e6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -19,7 +19,6 @@
 dist: precise

 

 jdk:

-  - openjdk6

   - openjdk7

   - oraclejdk8