This should finally allow us to adopt code style lints, as well
as others such as performance linting, and have them enforced by
the Github Actions continuous integration (CI) jobs.
For now, I'm choosing to depend on the 'panolint' gem from
Panorama Education, which is my current workplace, as I'd like
to adopt and stay consistent with the setting used there.
Changes
* Move development and test dependencies from gemspec to Gemfile
* Add dependency on 'panolint' gem
* Add .rubocop.yml
* Fix all existing issues
* Run rubocop in github actions CI
Based on: https://github.com/ruby/setup-ruby
Re: #60
Some notes on the initial Github Actions config:
1. Set min ruby version to 2.5 in order to support JRuby,
which as of 9.2.17.0 has a RUBY_VERSION of 2.5.
2. For CodeCov exclude JRuby and TruffleRuby, to avoid
errors sending the results in Github Actions on those
jobs rather than debugging them further.
3. Plan is to next remove Travis CI, and then to convert
the CodeCov config to use the Github Action for CodeCov
(thanks @taichi-ishitani for this suggestion!)
Marc Siegel