Log Message:
Update ruby-mocha to 0.12.3.

= 0.12.3
* Revert rename of undocumented internal module since it turns out
  Rails/ActiveSupport is relying on its existence.

= 0.12.2
* Officially support minitest v3.3.0 (still monkey-patching)

= 0.12.1
* Deprecation warning (instead of fail fast) if neither Test::Unit
  nor MiniTest is loaded. Fixes #88.
* Remove deprecated access to `Mocha::Standalone`.
* Remove the deprecated file `stubba.rb`.
* Officially support test-unit v2.5.1 (still monkey-patching).
* Improve the API acceptance test.

= 0.12.0
* Fail fast if neither Test::Unit nor MiniTest is loaded. Fixes #40.
* Officially support MiniTest up to v3.2.0 (still monkey-patching).
* Officially support test-unit v2.5.0 (still monkey-patching).
* Do not monkey-patch Test::Unit or MiniTest unless we *know* it's ok.
* Add acceptance tests to demonstrate using a block as a custom parameter
  matcher.
* Update Travis CI build status image to use the new build under the
  freerange account.