def add(name, options)
      @properties[name.to_sym] = Property.new(name.to_sym, options[:type], options[:default])
    end
def add(name, options)
      @properties[name.to_sym] = Property.new(name.to_sym, options[:type], options[:default])
    end
Add a property to the schema

 @param name [Symbol] the name of the property
 @param options [Hash] property options
 @option options [Symbol] :type The property type
 @option options [Symbol] :default The default value for the property
 @return [void]