Log Message:
Update ruby-rspec-rails to 3.3.1.

### 3.3.1 / 2015-06-14
[Full Changelog](http://github.com/rspec/rspec-rails/compare/v3.3.0...v3.3.1)

Bug Fixes:

* Fix regression that caused stubbing ActiveRecord model classes to
  trigger internal errors in rails. (Myron Marston, Aaron Kromer, #1395)