bug in _clean_params method does not properly handle NoneType request_params

[ieichen137]

when a route uses a parameter that is not python variable compliant, we have a function which naturally maps the input parameter to the correct one. this function fails when request params is none and the route uses one of the parameters which needs conversion.

[ieichen137]

glancing through the code, it looks like there's a good chance we don't need to pass in the request params at all.