Checking in changes prior to tagging of version v0.2.0

## [v0.2.0](https://github.com/natureglobal/go-letsencrypt-s3provider/compare/v0.1.0...v0.2.0) (2020-09-12)

* support PreferredChain [#7](https://github.com/natureglobal/go-letsencrypt-s3provider/pull/7) ([Songmu](https://github.com/Songmu))
* unexport internal interfaces [#6](https://github.com/natureglobal/go-letsencrypt-s3provider/pull/6) ([Songmu](https://github.com/Songmu))
* make svc and bucketName private fields of struct instead of package global var [#5](https://github.com/natureglobal/go-letsencrypt-s3provider/pull/5) ([Songmu](https://github.com/Songmu))
* move main package to cmd/go-letsencrypt-s3provider [#4](https://github.com/natureglobal/go-letsencrypt-s3provider/pull/4) ([Songmu](https://github.com/Songmu))

Checking in changes prior to tagging of version v0.1.0

## [v0.1.0](https://github.com/natureglobal/go-letsencrypt-s3provider/compare/3cda9a4124e5...v0.1.0) (2019-06-21)

* introduce go modules to lock dependencies [#3](https://github.com/natureglobal/go-letsencrypt-s3provider/pull/3) ([Songmu](https://github.com/Songmu))
* Migrate to officia go-aws-sdk from mitchelh/goamz [#2](https://github.com/natureglobal/go-letsencrypt-s3provider/pull/2) ([Songmu](https://github.com/Songmu))
* Update go-acme/lego to latest [#1](https://github.com/natureglobal/go-letsencrypt-s3provider/pull/1) ([Songmu](https://github.com/Songmu))