attempt to filter clang-tidy

.clang-tidy

@@ -21,7 +21,7 @@ readability-*,\
 -readability-else-after-return,\
 "
 WarningsAsErrors: '*'
-HeaderFilterRegex: '.*'
+HeaderFilterRegex: '.*/(src|test-src)/*'
 CheckOptions:
   - key:   modernize-use-default-member-init.UseAssignment
     value: '1'