language: ruby
rvm:
  - 2.0.0-p598
  - 2.1.6
  - 2.2.0
  - 2.2.2
  - ruby-head
matrix:
  allow_failures:
    # One (ruby 2.3-dev) test fails, due to a change of behaviour in Array#delete_if,
    # but I don't know if this is intentional. I'll fix it once the behaviour change is documented.
    # For now, I don't really care if 2.3-dev tests all pass.
    - rvm: ruby-head