language: ruby
rvm:
  - 1.9.3
  - 2.0.0
  - 2.1.0
matrix:
  allow_failures:
    - rvm: 2.1.0

language: ruby
rvm:
  - 1.9.3
  - 2.0.0
  - ruby-head
matrix:
  allow_failures:
    - rvm: ruby-head

Use "ruby-head" instead of "2.1.0"
Use "ruby-head" instead of "2.1.0"

Because "ruby-head" version on Travis CI automatically updates.
