Support yardoc

This commit renames the .rb template to .erb. With it renamed, yardoc
won't try and parse the file (which was causing the install to break).

Closes #52

lib/generators/factory_girl/model/model_generator.rb

@@ -7,7 +7,7 @@ module FactoryGirl
       class_option :dir, :type => :string, :default => "test/factories", :desc => "The directory where the factories should go"
       
       def create_fixture_file
-        template 'fixtures.rb', File.join(options[:dir], "#{table_name}.rb")
+        template 'fixtures.erb', File.join(options[:dir], "#{table_name}.rb")
       end
     end
   end