fixed rspec 2.0.0.beta.22 deprecation

Rakefile

@@ -4,7 +4,7 @@ begin
   require "rspec/core/rake_task"
 
   RSpec::Core::RakeTask.new do |t|
-    t.spec_opts = %w(-fd -c)
+    t.rspec_opts = %w(-fd -c)
   end
 rescue LoadError
   desc message = %{"gem install rspec --pre" to run the specs}