Release v2

[at-wat]

Migrating to aws-sdk-go-v2 breaks the API. So, the major version of s3sync will be bumped.

Planned breaking changes:

• Migrate to aws-sdk-go-v2 (Migrate to aws-sdk-go-v2 #400)
• Drop Sync without context.Context and rename SyncWithContext to Sync
• Simplify logger interface (Migrate sync log to awscli v2 style #414)
• Update README
  • Update example usage
  • Add migration guide

[akuntsch]

@at-wat as far as I can see all the changes are merged?

Would love a new release.

[at-wat]

@akuntsch I created https://github.com/seqsense/s3sync/releases/tag/v2.0.0-rc.0
Please try it!

I also noticed that we forgot to update the README.

[akuntsch]

@akuntsch I created https://github.com/seqsense/s3sync/releases/tag/v2.0.0-rc.0 Please try it!

I also noticed that we forgot to update the README.

Looks good and seems to work as before. Thanks!