moved the proxy path setting.  Fixes #27

In the case where `serviceValidate()` is placed before `proxyTicket()` middleware, it is possible for the options.pathname to be modified [service-validate:30](https://github.com/AceMetrix/connect-cas/blob/master/lib/service-validate.js#L30).

Since `proxyTicket` middleware does not subsequently overwrite this value, when connect calls the function, it will use the wrong pathname to verify.

This PR moves the value to after the handler so that `proxyTicket` can overwrite the value like the other middleware.