RPC v0.9.0

Summary

transports/websocket has been rewritten from scratch.

It uses github.com/sourcegraph/jsonrpc2 and github.com/gorilla/websocket now.

The transport package should be more robust. The code is much less
messy and it uses up-to-date packages.

The transport API is also changes. You can now pass multiple WebSocket
endpoint URLs and the auto-reconnect logic will use round-robin to
rotate between the URLs provided.

Commits

f4bba9c transport/websocket: Rewrite from scratch