Support athena workgroups

[nianglao]

AWS release workgroups for Athena to support tags.
https://aws.amazon.com/about-aws/whats-new/2019/02/athena_support_for_tags/
Tagging Workgroups allows you to allocate costs, get detailed billing reports across Workgroups as well as define IAM permissions on Workgroups based on these tags

There is an PR by @jkatagi #26

Can anyone help review and merge this?

[muroon]

Recently, we released speee/go-athena.

We have already merged the PR related to this issue and can keep maintaining this library and review / merge your PRs.
In addition, we added the following new features.

• Add Docker environment
• Add reviewdog configuration for linting
• Remove Result Header when executing DDL
• Use workgroup
• Update tests (make each package up to date)
• Introduce Result Mode (Query result acquisition mode)

Especially, we think the Result Mode is a cool feature, and we summarized the feature here.
Please check and try to use it!