Version v0.3.0

= New Features

- Added `serf query` methods:
  - Villein::Client#query(name, payload, ...)
  - Villein::Agent#respond(name) { |event| ... }
- Villein::Client#info, Agent#info for `serf info`
  - Available on serf v0.6.0 or later
  - On Villein::Client, initialize method now attempts to fetch node
    name using Client#info method, when `name` parameter is ommitted

= Enhancements

- Exception during event handler now appear in stderr