Log Message:
Update ruby-rspec-core to 3.3.2.

### 3.3.2 / 2015-07-15
[Full Changelog](http://github.com/rspec/rspec-core/compare/v3.3.1...v3.3.2)

Bug Fixes:

* Fix formatters to handle exceptions for which `backtrace` returns `nil`.
  (Myron Marston, #2023)
* Fix duplicate formatter detection so that it allows subclasses of formatters
  to be added. (Sebastián Tello, #2019)

### 3.3.1 / 2015-06-18
[Full Changelog](http://github.com/rspec/rspec-core/compare/v3.3.0...v3.3.1)

Bug Fixes:

* Correctly run `before(:suite)` (and friends) in the context of an example
  group instance, thus making the expected RSpec environment available.
  (Jon Rowe, #1986)