sudo: false
language: ruby
rvm:
  - '2.2.9'
  - '2.3.6'
  - '2.4.3'
  - '2.5.0'
  - jruby-9.1.15.0
before_install:
  - gem update --system
  - gem install bundler -v 1.16.1

sudo: false
cache: bundler
language: ruby
rvm:
  - '2.2.10'
  - '2.3.7'
  - '2.4.4'
  - '2.5.1'
  - jruby-9.2.0.0
before_install:
  - gem update --system
  - gem update --remote bundler

Update Ruby versions on Travis-CI
Update Ruby versions on Travis-CI