Merge pull request #16613 from splattael/master

Speed up JRuby tests by improving the startup time

.travis.yml

@@ -10,6 +10,9 @@ rvm:
   - rbx-2
   - jruby
 env:
+  global:
+    - JRUBY_OPTS='-J-XX:+TieredCompilation -J-XX:TieredStopAtLevel=1 -J-Djruby.compile.mode=OFF -J-Djruby.compile.invokedynamic=false -J-Xmx1024M'
+  matrix:
     - "GEM=railties"
     - "GEM=ap"
     - "GEM=am,amo,as,av,aj"