Monkey patch for https://github.com/rails/rails/pull/12425#issuecomment-38069331

mysql_boolean_uniqueness.rb

if Rails::VERSION::MAJOR >= 4
  if Rails::VERSION::MINOR > 0
    ActiveSupport::Deprecation.warn("This patch is probably not useful anymore. Check if https://github.com/rails/rails/pull/12425 have been released.")
  end

  class ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter

    def type_cast(value, column)
      case value
      when TrueClass
        1
      when FalseClass
        0
      else
        super
      end
    end

  end
end