Fix typo, and add test for ActionView

lib/rucaptcha.rb

@@ -39,6 +39,6 @@ ActiveSupport.on_load(:action_controller) do
   ActionController::Base.send :include, RuCaptcha::ControllerHelpers
 end
 
-ActiveSupport.on_load(:active_view) do
+ActiveSupport.on_load(:action_view) do
   include RuCaptcha::ViewHelpers
 end

spec/view_spec.rb

@@ -0,0 +1,10 @@
+require 'spec_helper'
+
+describe ActionView::Base do
+  describe '.rucaptcha_input_tag' do
+    it 'should work' do
+      view = ActionView::Base.new
+      expect(view.respond_to?(:rucaptcha_input_tag)).to eq true
+    end
+  end
+end