Merge pull request #8 from kayac/modernization

update deps

Merge pull request #6 from kayac/raw-message

Raw message

set binary name

charset=utf-8

set AuthenticateOnUnsubscribe to "no"

To keep a backward compatibility.

pathed name in S3

Add .txt extention for local storage.

no need to add .txt extentions.

Merge pull request #4 from kayac/go-config

use kayac/go-config

Merge pull request #3 from kayac/s3

Support S3 storage