Tutorial - Authentication.lhs - does not compile for these reasons

Hi --

There are overlapping definitions for Unauthorized, BasicAuthCheck. It might be useful to flag the "ignore" where the overlap exists. Also, Typeable is deprecated. The code excludes the language pragma but continues to include it in the derive clauses.

The tutorials are solid and greatly appreciated. So much so, it takes me time to realize "it's not me, it's the code :))"

Thank you.