I'm not a fan of the `required` argument.

Maybe it could be more expressively named?  `ignore_missing_file=True`?  `raise_if_missing=False`?

Or perhaps it should accept (and pass through) `filename`, and then `load()` should see if it got a file-like object and pass it directly to config.readfp()?  Let me continue in a line note for the load method.