Add `rubocop` to Gemfile and gemspec
Solve rubocop cautions exclude no-doc cautions
Merge pull request #1 from huyu398/fit_rubocop

Fit to rubocop rules
Assign using gems version
Setting homepage of `rubbitter`
Write a short summary
Ignore long line caution
Merge pull request #2 from huyu398/improve_setting

Improve settings
Merge pull request #3 from huyu398/develop

Release version 0.1.0