Sort plurals forms in CLDR order

Instead of alphabetical, sort these in the expect CLDR order
zero...other

Only sort when retreiving the values for formatter consumption, this
should leave Twine files in their default order.

Signed-off-by: Dwayne Bailey <dwayne@translatehouse.co.uk>

lib/twine/twine_file.rb

@@ -58,7 +58,7 @@ module Twine
 
     def plural_translation_for_lang(lang)
       if @plural_translations.has_key? lang
-        @plural_translations[lang].dup
+        @plural_translations[lang].dup.sort_by { |key,_| TwineDefinition::PLURAL_KEYS.index(key) }.to_h
       end
     end