dev: update Guardfile to run everything when matchers change

Author: dchelimsky

Guardfile

@@ -2,5 +2,5 @@ guard 'rspec', :version => 2 do
   watch(/^spec\/(.*)_spec.rb/)
   watch(/^lib\/(.*)\.rb/)         { |m| "spec/#{m[1]}_spec.rb" }
   watch(/^spec\/spec_helper.rb/)  { "spec" }
-  watch(/^lib\/rspec\/matchers\/built_in.rb/)  { "spec" }
+  watch(/^lib\/rspec\/matchers\/built_in/)  { "spec" }
 end