language: ruby
sudo: false
cache: bundler
rvm:
  - 2.0.0
  - 2.1.8
  - 2.2.4
  - 2.3.0
before_install:
  - gem update bundler

language: ruby
sudo: false
cache: bundler
rvm:
  - 2.1.10
  - 2.2.5
  - 2.3.1
before_install:
  - gem update bundler

Test against latest Ruby versions
Test against latest Ruby versions