travis.yml: Choose dist trusty to fix Java 8
The upgrade to Xenial broke Java 8, as Trusty contained Java 8 whereas
Xenial uses Java 11. So this "flipped" which version was necessary to be
downloaded from Java 11 to Java 8. And Java 8 is not supported by
install-jdk.sh.
Workaround as seen at:
https://travis-ci.community/t/oracle-jdk-11-and-10-are-pre-installed-not-the-openjdk-builds/785/16
I hope this is temporary.
diff --git a/.travis.yml b/.travis.yml
index 2e4bf15..f81dec9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -45,6 +45,8 @@
# This image comes with jdk8
osx_image: xcode7
+dist: trusty
+
notifications:
email: false
