use version 1.x of with_model to avoid errors in class comparisons

Gemfile

@@ -4,7 +4,7 @@ case ENV["MODEL_ADAPTER"]
 when nil, "active_record"
   gem "sqlite3"
   gem "activerecord", '~> 3.0.9', :require => "active_record"
-  gem "with_model"
+  gem "with_model", '~> 0.1.5'
   gem "meta_where"
 when "data_mapper"
   gem "dm-core", "~> 1.0.2"