Fix Rakefile to actually use RSpec 1.3

Author: indirect

Rakefile

@@ -1,10 +1,10 @@
 require 'bundler'
 Bundler::GemHelper.install_tasks
 
-require "rspec/core/rake_task"
+require "spec/rake/spectask"
 desc "Run all examples"
-RSpec::Core::RakeTask.new(:spec) do |t|
+Spec::Rake::SpecTask.new(:spec) do |t|
   t.ruby_opts  = ['-r test/unit']
-  t.rspec_opts = %w[--color]
+  t.spec_opts = %w[--color]
 end
 task :default => :spec