v0.2.0

* Support verbose and summary logging (#27)
* Consolidate request handling logic (#29 & #30)
* Cleanups to `Sanford` module (#31)
* Make hosts singletons (#32)
* Performance improvements (#34)
* Add `Runner` concept (#35)
* Add `before_init` and `after_init` callbacks (#36)
* Change exception handling hook to `error` block on host (#37)
* Added distribution list to benchmark report (#38)