Specify ActiveRecord::Base to call parse_options
this method conflicts between acts-as-taggable-on and flag_shih_tzu
https://github.com/pboling/flag_shih_tzu/blob/master/lib/flag_shih_tzu.rb#L250
Merge pull request #1 from dex1t/specify-class-name

Specify ActiveRecord::Base to call parse_options