adding rake dep explicitly

noah.gemspec

@@ -51,4 +51,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency("rspec", ["~> 2.5"])
   s.add_development_dependency("rcov", ["= 0.9.9"])
   s.add_development_dependency("rack-test", ["= 0.5.7"])
+  s.add_development_dependency("rake", ["= 0.8.7"])
 end