language: ruby
rvm:
  - 2.0.0
  - 2.1.7
  - 2.2.3

language: ruby
rvm:
  - 2.1.10
  - 2.2.7
  - 2.3.4
  - 2.4.1

Add ruby2.4.1 and drop ruby2.0.0 for Travis CI
Add ruby2.4.1 and drop ruby2.0.0 for Travis CI
