Use proper logger for REST-API WSGIServer
Use proper logger for REST-API WSGIServer

Prior to this change, all requests to the WSGIServer ended up in
sys.stderr. With using a proper logger, we can have them inside the
standard logs of the application.

tomashaber/raiden,tomashaber/raiden,tomashaber/raiden,hackaugusto/raiden,hackaugusto/raiden,tomashaber/raiden,tomashaber/raiden