Attempting fix failing release.

Problem in Travis:
Expected feature release number in range of 9 to 15, but got: 8

The command "~/bin/install-jdk.sh --target "/home/travis/oraclejdk8"
--workspace "/home/travis/.cache/install-jdk" --feature "8"
--license "BCL"" failed and exited with 3 during .

Fix proposal:
https://travis-ci.community/t/error-installing-oraclejdk8-expected-feature-release-number-in-range-of-9-to-14-but-got-8/3766/10

.travis.yml

@@ -33,6 +33,8 @@ cache:
 
 language: groovy
 
+dist: trusty
+
 jdk:
 - oraclejdk8