add test coverage for tag list default name

test/is_taggable_test.rb

@@ -8,6 +8,11 @@
   expect Tagging do
     Post.new.taggings.build
   end
+
+  expect ["is_taggable", "has 'tags' by default"] do
+    n = Comment.new :tag_list => "is_taggable, has 'tags' by default"
+    n.tag_list
+  end
 
   expect ["something cool", "something else cool"] do
     p = Post.new :tag_list => "something cool, something else cool"

test/test_helper.rb

@@ -11,6 +11,9 @@
 ActiveRecord::Base.logger.level = Logger::WARN
 
 ActiveRecord::Schema.define(:version => 0) do
+  create_table :comments do |t|
+  end
+
   create_table :posts do |t|
     t.string  :title, :default => ''
   end
@@ -32,3 +35,6 @@ class Post < ActiveRecord::Base
   is_taggable :tags, :languages
 end
 
+class Comment < ActiveRecord::Base
+  is_taggable
+end