function registerClient(alias, urlToWsdl, clientStub) {
  aliasedClientStubs[alias] = clientStub;
  clientStubs[urlToWsdl] = clientStub;
}
Registers a stubbed client with soap-stub.  urlToWsdl is the path you will use
in your app.

@param {String} alias A simple name to refer to the clientStub as.
@param {String} urlToWsdl May be file system URL or http URL.
@param {Object} clientStub A client with stubbed methods.