Test pass: test_destroy

Expand Targets #update success flash and failure handling
Add Target index table checks in modification actions tests

app/models/validations/nested_uniqueness.rb

@@ -63,6 +63,7 @@ module Validations::NestedUniqueness
         end
       end
       if records
+        # TODO: reset collction, not proxy
         collection.proxy_association.reset
         records.each { |r| collection.proxy_association.add_to_target(r) }
       end