correct check for 3-2-stable

Author: JonRowe

Gemfile

@@ -31,6 +31,6 @@ else
   gem "activesupport", version
 end
 
-gem "test-unit", '~> 3' if version >= '3.2.22' && version < '4.0.0'
+gem "test-unit", '~> 3' if (version >= '3.2.22' || version == '3-2-stable') && version < '4.0.0'
 
 gem "i18n", '< 0.7.0' if RUBY_VERSION < '1.9.3'

spec/rspec/active_model/mocks/mock_model_spec.rb

@@ -424,7 +424,7 @@
           gem 'minitest' if defined?(Kernel.gem)
           require 'minitest/unit'
           include MiniTest::Assertions
-        elsif version >= '3.2.22'
+        elsif version >= '3.2.22' || version == '3-2-stable'
           begin
             # Test::Unit "helpfully" sets up autoload for its `AutoRunner`.
             # While we do not reference it directly, when we load the `TestCase`