Un copy-pasta the requirement for 'set'

kpaulisse · kpaulisse · commit 153cea5bd288 · 2017-12-17T09:48:23.000-06:00
diff --git a/lib/octocatalog-diff/catalog-diff/filter/single_item_array.rb b/lib/octocatalog-diff/catalog-diff/filter/single_item_array.rb
@@ -2,8 +2,6 @@
 
 require_relative '../filter'
 
-require 'set'
-
 module OctocatalogDiff
   module CatalogDiff
     class Filter
