1.4.0

Changelog

08c087a Add Godoc
9cc9216 Better error management: close channel rather than Exit
649c437 Fix version number
ebd7642 Refactor to make the cloudwatch package more like a library consumable by other projects
b5ebf20 Update README.md
286c62c Update README.md
8563bfd add goreleaser
db6ade7 add goreleaser brew recipe details
b05c6a6 more doc
9c8d95b refresh log stream lists for any available channel
667a61a some badges
05bcebc update license badge