Fix specs for Relation::Aliases::AttributeIndex#field

Kills the following mutation:

def renamed_entries(aliases) 
  aliases.each_with_object(entries.dup) do |(from, to), renamed|
  - with_initial_attributes(from) do |initial, _current| 
  + with_initial_attributes(from) do |initial| 
    renamed[initial] = new_attribute(to, initial.prefix) 
  end 
end 
Fix specs for Relation::Aliases::AttributeIndex#rename

Kills the following mutation:

@@ -1,6 +1,6 @@
 def with_entries(name, filter)
   entries.each do |initial, current|
-    if filter.call(name, current)
+    if filter
       yield(initial, current)
     end
   end
 end
Fix specs for Relation::Aliases::AttributeIndex#rename_relations

Kills the following mutation:

@@ -1,6 +1,6 @@
 def with_entries(name, filter)
   entries.each do |initial, current|
-    if filter.call(name, current)
+    if filter
       yield(initial, current)
     end
   end
 end