Add backwards compatibility define_singleton_method for Ruby 1.8.

spec/spec_helper.rb

@@ -1,8 +1,11 @@
+require 'rubygems' if VERSION =~ /^1.8/
 gem 'minitest'
 require 'minitest/spec'
 require 'minitest/autorun'
 require 'minitest/matchers'
 
+require 'process_shared'
+
 class RangeMatcher
   def initialize(operator, limit)
     @operator = operator.to_sym