Make railties an optional dependency

lib/vanilla/ujs.rb

@@ -1,8 +1,9 @@
-require 'vanilla/ujs/version'
-require 'vanilla/ujs/rails'
-
 module Vanilla
-  module Rails
-    # Your code goes here...
+  module Ujs
+    require 'vanilla/ujs/version'
+
+    if defined?(Rails)
+      require 'vanilla/ujs/rails'
+    end
   end
 end

vanilla-ujs.gemspec

@@ -19,7 +19,6 @@ Gem::Specification.new do |spec|
 
   spec.required_rubygems_version = '>= 1.3.6'
 
-  spec.add_dependency 'railties', '>= 4.2.0'
-
+  spec.add_development_dependency 'railties', '>= 4.2.0'
   spec.add_development_dependency 'bundler', '~> 1.11'
 end