travis: use jdk v8

maxgalbu · maxgalbu · commit c5d98cbd0e2c · 2017-06-29T16:40:26.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -16,3 +16,4 @@ before_install:
     - "export DISPLAY=:99.0"
     - "sh -e /etc/init.d/xvfb start"
     - sleep 3
+    - jdk_switcher use oraclejdk8
