Ensure `Relation` responds to `shuffle`

It appears that I missed this one when I delegated all the non-mutation
array methods that were not on Enumerable

activerecord/lib/active_record/relation/delegation.rb

@@ -37,7 +37,7 @@ def inherited(child_class)
     # for each different klass, and the delegations are compiled into that subclass only.
 
     delegate :to_xml, :to_yaml, :length, :collect, :map, :each, :all?, :include?, :to_ary, :join,
-      :[], :&, :|, :+, :-, :sample, :reverse, :compact, to: :to_a
+      :[], :&, :|, :+, :-, :sample, :shuffle, :reverse, :compact, to: :to_a
 
     delegate :table_name, :quoted_table_name, :primary_key, :quoted_primary_key,
              :connection, :columns_hash, :to => :klass

activerecord/test/cases/relation/delegation_test.rb

@@ -27,7 +27,7 @@ def call_method(target, method)
 
   module DelegationWhitelistBlacklistTests
     ARRAY_DELEGATES = [
-      :+, :-, :|, :&, :[],
+      :+, :-, :|, :&, :[], :shuffle,
       :all?, :collect, :compact, :detect, :each, :each_cons, :each_with_index,
       :exclude?, :find_all, :flat_map, :group_by, :include?, :length,
       :map, :none?, :one?, :partition, :reject, :reverse,