Things to-do

[CGA1123]

• Document Configuration options
• Abstract away dependency on redis?
• Full end-to-end test using some app = proc { [200, {}, []] }
• Probably more docs 😛
• Configurable logger
• add a verify! after Umbra.configure yields? (done for redis connection)
• Add ability to set tolerance to throttle shadowing (e.g exponential backoff when P99 > x ms)