V0.4.0 V2 API Support

Breaking Change

This version no longer support the V1 backend API. If you have a V1 API running, please consider switching to V2 API, or use hosted https://api.broker.bgpkit.com/v2 as the broker_url.

What's Changed

• Support V2 broker API by @digizeph in #3

Full Changelog: v0.3.2...v0.4.0