Improved test coverage

- Added tests for handshakes in namespaces (one roundtrip)
- Replaced misleading 'handshake' with 'authentication', where the second roundtrip is used

lib/index.js

@@ -114,7 +114,7 @@ function noQsMethod (options) {
   };
 }
 
-function authorize (options, onConnection) {
+function authorize (options) {
   options = xtend({ decodedPropertyName: 'decoded_token', encodedPropertyName: 'encoded_token' }, options);
 
   if (typeof options.secret !== 'string' && typeof options.secret !== 'function') {