language: ruby
rvm:
  - 2.3.3
  - 2.4.0

notifications:
  email:
    on_success: change

language: ruby
rvm:
  - 2.3
  - 2.4

notifications:
  email:
    on_success: change

Remove patch-versions of Ruby for Travis CI
Remove patch-versions of Ruby for Travis CI

Use pre-builded versions now.
