v0.4.0: 12/04/2019

- Modified retry package to use backoff package for exponential backoffs on retries [#21](https://github.com/xmidt-org/codex-db/pull/21)
- Added automated releases using travis [#22](https://github.com/xmidt-org/codex-db/pull/22)