Add support for latest versions of packages about edx-lint

[nedbat]

Thanks, we are in the process of enabling dependabot across our repos to help us stay current. Updating pylint in particular is tricky because it tends to shift around where the violations are reported.

[sshishov]

@nedbat agree, it is difficult to support the latest 3rd party project. But you can start supporting it from some version and if someone is using old version, let them install old package of edx-lint.

btw, when do you plan to enable this dependabot?

[nedbat]

These days, we aren't looking at dependabot, but we have other ideas for how to stay current. The next thing to do is to make this repo conform to OEP-18