Merge pull request #7 from okuzawats/update-rubocop

apply bundle update

use 1.28 or later

update .rubocop.yml

add comment to rubocop action

Merge pull request #6 from okuzawats/use-checkout-v3

use checkout@v3 instead v2

Merge pull request #5 from okuzawats/fix-ruby-version

remove trailing break

Merge pull request #4 from okuzawats/use-ruby-3.1.0

use ruby 3.1.0

fix yaml syntax

update README.md

Merge pull request #3 from okuzawats/rake

fix unit test workflow with rake test