[skip ci] Travis: switch to openjdk8

Author: colinsurprenant

.travis.yml

@@ -29,19 +29,25 @@ matrix:
   - rvm: jruby-1.7.27
     env: LOGSTASH_BRANCH=5.6
   - rvm: jruby-1.7.27
-    env: DISTRIBUTION=legacy INTEGRATION=true ES_VERSION=5.6.13 LOGSTASH_BRANCH=5.6 TEST_DEBUG=true
+    env: DISTRIBUTION=legacy INTEGRATION=true ES_VERSION=5.6.13 LOGSTASH_BRANCH=5.6
+      TEST_DEBUG=true
   - rvm: jruby-9.1.13.0
-    env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-6 LOGSTASH_BRANCH=6.7 TEST_DEBUG=true
+    env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-6 LOGSTASH_BRANCH=6.7
+      TEST_DEBUG=true
   - rvm: jruby-9.1.13.0
-    env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-7 ARCH=LINUX LOGSTASH_BRANCH=7.x TEST_DEBUG=true
+    env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-7 ARCH=LINUX
+      LOGSTASH_BRANCH=7.x TEST_DEBUG=true
   - rvm: jruby-9.1.13.0
-    env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-8 ARCH=LINUX LOGSTASH_BRANCH=master TEST_DEBUG=true
+    env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-8 ARCH=LINUX
+      LOGSTASH_BRANCH=master TEST_DEBUG=true
   allow_failures:
-  - env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-8 ARCH=LINUX TEST_DEBUG=true
+  - env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-8 ARCH=LINUX
+      TEST_DEBUG=true
   - rvm: jruby-9.1.13.0
-    env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-8 ARCH=LINUX LOGSTASH_BRANCH=master TEST_DEBUG=true
+    env: DISTRIBUTION=default INTEGRATION=true ES_VERSION=LATEST-SNAPSHOT-8 ARCH=LINUX
+      LOGSTASH_BRANCH=master TEST_DEBUG=true
   fast_finish: true
 install: true
 script: ci/build.sh
-jdk: oraclejdk8
+jdk: openjdk8
 before_install: gem install bundler -v '< 2'