rvm:
  - 1.8.7
  - 1.9.1
  - 1.9.2
  - ree
  - rbx
  - rbx-2.0
  - jruby

rvm:
  - 1.8.7
  - 1.9.1
  - 1.9.2
  - ruby-head
  - ree
  - rbx
  - rbx-2.0
  - jruby

Revert "don't build on ruby-head"
Revert "don't build on ruby-head"

This reverts commit 378ae530ca6da1cb99f27d0bf1876a08a847abdd.
