[ci] minimize travis CI (to be dropped)

Author: kares

.travis.yml

@@ -2,13 +2,11 @@ language: ruby
 
 dist: precise # due OpenJDK 7
 jdk:
-  - openjdk8
   - openjdk11
-  - openjdk15
 
 rvm:
   - jruby-9.2.19.0
-  - jruby-9.3.1.0
+  - jruby-9.3.3.0
 
 before_install:
   - unset _JAVA_OPTIONS
@@ -20,7 +18,7 @@ install: if [[ "$BUNDLE_INSTALL" != 0 ]]; then jruby -S bundle install; else tru
 
 before_script:
   - if [[ "$BUNDLE_INSTALL" != 0 ]]; then jruby -rbundler/setup -S rake test_prepare; else true; fi
-  #- export JRUBY_OPTS="-Xjit.threshold=0"
+  - export JRUBY_OPTS="$JRUBY_OPTS -Xjit.threshold=0"
 script: jruby -rbundler/setup -S rake test
 
 matrix:
@@ -29,38 +27,16 @@ matrix:
     - rvm: jruby-head
     - script: jruby -rbundler/setup -S rake integration:install integration:test
   include:
-    - jdk: openjdk8
-      rvm: jruby-9.1.13.0
-    - jdk: oraclejdk8
-      rvm: jruby-9.1.17.0
     - jdk: openjdk11
       rvm: jruby-head
-    - jdk: openjdk11
-      rvm: jruby-9.2.12.0
-    #
-#    - jdk: openjdk8
-#      rvm: jruby-9.1.17.0
-#      env: BUNDLE_INSTALL=0
-#      script: mvn verify -P test
-#    - jdk: oraclejdk8
-#      rvm: jruby-9.2.12.0
-#      env: BUNDLE_INSTALL=0
-#      script: mvn verify -P test
-    #
+    - jdk: openjdk17
+      rvm: jruby-9.3.3.0
     - jdk: openjdk8
       rvm: jruby-9.1.17.0
       script: jruby -rbundler/setup -S rake integration:install integration:test
     - jdk: oraclejdk11
-      rvm: jruby-9.2.12.0
+      rvm: jruby-9.2.20.0
       script: jruby -rbundler/setup -S rake integration:install integration:test
-notifications:
-  irc:
-    channels:
-      - "irc.freenode.org#jruby"
-    on_success: change
-    template:
-      - "%{repository} (%{branch}:%{commit} by %{author}): %{message} (%{build_url})"
-    skip_join: true
 
 cache:
   directories: