Fix binstub typo to generate rails command.

Author: cupakromer

Rakefile

@@ -59,7 +59,7 @@ namespace :generate do
           sh "bundle install --gemfile ./Gemfile --path ../../../bundle"
           # Rails 4 cannot use a `rails` binstub generated by Bundler
           sh "bundle binstubs rspec-core rake --force"
-          sh "bundle binstubs rails" unless File.exist?("bin/rails")
+          sh "bundle binstubs railties" unless File.exist?("bin/rails")
 
           application_file = File.read("config/application.rb")
           sh "rm config/application.rb"