Merge pull request #55 from ensan-hcl/refactoring/lint

[Refactoring] apply lint

Merge pull request #53 from ensan-hcl/feature/upper_lower_key

[Feature] add upper_lower key

Merge pull request #51 from ensan-hcl/develop_v1.2

[Release] Version 1.2

Merge pull request #46 from ensan-hcl/release/1.1

Release 1.1

Merge pull request #23 from ensan-hcl/arraywrite

Add implementation of `write` for list of custard