Require Java 8 in travis build

Change-Id: Ifb197048e25c59cefd991577e22460bf1332b40c
diff --git a/.travis.yml b/.travis.yml
index 34878aa..5405db8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,12 @@
 #
 
 language: java
+sudo: false
+addons:
+  apt:
+    packages:
+      - oracle-java8-installer
+jdk: oraclejdk8
 
 install:
   - cd ..