package: bump ws to 0.4.30
websocket: remove the "bufferedAmount" checking logic

This code was buggy to begin with, and actually the underlying
technique being used was non-deterministic and wouldn't work in practice
anyways.

The WebSocket client API kinda sucks in this regard, since it's virtually
impossible to implement proper ACKs using the WebSocket API by itself.
test: re-enable the "agent" option tests
Merge pull request #194 from LearnBoost/update/fixes

Upgrade to ws v0.4.30 + fixes