rvm:
  - 2.1.0
  - 2.1.1
  - 2.2.2
  - 2.3.0
  - 2.4.0
  - jruby-9.2.7.0
jdk:
  - oraclejdk9
before_install:
 - sudo apt-get update
 - sudo apt-get install libicu-dev