socket.io vendor in tests

Current socket.io vendor in test is probably outdated, it still relies on `new Buffer` so if you run tests it show deprecation warnings. At some point node will probably remove constructors.

I am leaving this as issue right now, so we don't forget to address this.

Locate the socket.io vendor used by the tests and inspect the `new Buffer` calls that produce warnings. Identify the appropriate updated vendor source, then run the test suite and confirm the deprecation warnings are gone without changing test behavior.

Written by the indexing model from the issue text.