language: ruby
rvm:
  - 2.1.0
  - 2.2.0
  - 2.3.0
  - 2.4.0

language: ruby
rvm:
  - 2.1.9
  - 2.2.0
  - 2.3.0
  - 2.4.0

Use 2.1.9 because rvm does not found ruby-2.1.0
Use 2.1.9 because rvm does not found ruby-2.1.0
