Add Dependabot for GitHub Actions

[petergoldstein]

As the checkout action in the configuration is out of date, Dependabot should open a PR to update the action after this is merged.

[ddnexus]

This solves the bug in rubocop that complains for the "redundant initializer" and also complains for the Unnecessary disabling of Style/RedundantInitialize if you disable it with inlining # rubocop:disable Style/RedundantInitialize 🤷

In the v6 branch I added a dummy line in order to avoid the global exclude of a single file, wondering which one is "better"

[petergoldstein]

@ddnexus Just let me know how you'd prefer to handle it and I can make any change necessary. I don't have a strong preference here.

[ddnexus]

I'll go with yours.

Please, could you revert my dummy line, and add some comment like # cannot inline the disabling in the file because rubocop complains anyway comment on top of the exclude in .rubocop.yml. Thank you.

(I tried to do it myself rebasing your branch on v6 but when I tried to push it to your branch, there was a long list of commits added below yours, and I didn't wanted to mess up your branch. Github Squash and merge will sort it out.)

[petergoldstein]

@ddnexus I've made these changes. Please let me know if anything else is required. Thanks.

[benkoshy]

What does it do?

It checks whether any the github actions in the .workflow directory are out of date. If they are, it creates a PR for the latest version.

This PR looks good, checks out (pun intended), and complies with what Github recommends (see reference documentation here).

Re the Rubocop commit - not sure whether the maintainer would prefer the master or v6 branch?

[ddnexus]

hmmm... I actually completely disabled dependabot because it complains for too many things that are not important for the gem itself. Just too annoying to keep up with it 🙃

[ddnexus]

Just noticed (thanks @benkoshy) that is checking the github-actions, which is actually very useful!

[ddnexus]

Thank you @petergoldstein