Make diffs in dup_consistency files part of scheme

Previously, changing a duplicate_consistency file would be
considered a 'global' change, resulting in CI re-running all tests
for all schemes.

test/helpers.py

@@ -173,13 +173,17 @@ def permit_test(testname, thing, *args, **kwargs):
             for diff_line in diff_result.stdout.decode('utf-8').splitlines():
                 # don't skip test if there are any changes outside schemes
                 if (not diff_line.startswith('crypto_kem') and
-                        not diff_line.startswith('crypto_sign')):
+                        not diff_line.startswith('crypto_sign') and
+                        not diff_line.startswith(os.path.join('test', 'duplicate_consistency'))):
                     logging.info("Running all tests as there are changes "
                                  "outside of schemes")
                     return True
                 # do test if the scheme in question has been changed
                 if diff_line.startswith(thing.path(base='')):
                     return True
+                # do test if the scheme's duplicate_consistency files have been changed
+                if diff_line.startswith(os.path.join('test', 'duplicate_consistency', scheme.name.lower())):
+                    return True
             # there were no changes outside schemes, and the scheme in question had no diffs
             return False