Downgrading to Java 1.7

Necessary to keep compatibility with Android

Change-Id: I6520dc649cb1b44f61a8cb7bc054eda7d818082c
diff --git a/.travis.yml b/.travis.yml
index 9bcf999..e358d25 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,3 @@
 language: java
 jdk:
-  - oraclejdk8
+  - oraclejdk7