Remove unnecessary method

Author: zmoazeni

lib/csscss/types.rb

@@ -1,9 +1,5 @@
 module Csscss
   Declaration = Struct.new(:property, :value, :parents) do
-    def self.from_csspool(dec)
-      new(dec.property.to_s.downcase, dec.expressions.join(" ").downcase)
-    end
-
     def self.from_parser(property, value, clean = true)
       value = value.to_s
       property = property.to_s