Complete pip-tools setup (backport #5486)

[greshilov]

What do these changes do?

Backport #5486.

Are there changes in behavior for the user?

No.

Related issue number

Checklist

• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• If you provide code modification, please add yourself to CONTRIBUTORS.txt
  • The format is <Name> <Surname>.
  • Please keep alphabetical order, the file is sorted by names.
• Add a new news fragment into the CHANGES folder
  • name it <issue_id>.<type> for example (588.bugfix)
  • if you don't have an issue_id change it to the pr id after creating the pr
  • ensure type is one of the following:
    • .feature: Signifying a new feature.
    • .bugfix: Signifying a bug fix.
    • .doc: Signifying a documentation improvement.
    • .removal: Signifying a deprecation or removal of public API.
    • .misc: A ticket has been closed, but it is not of interest to users.
  • Make sure to use full sentences with correct case and punctuation, for example: "Fix issue with non-ascii contents in doctest text files."

[webknjaz]

@greshilov when it's WIP, it's best to turn the PR into a draft

[greshilov]

@webknjaz PTAL

Unfortunately, I had to consider python version to produce valid requirements. The most interesting commit is 5f0637f.

If the presented approach is OK, we probably need some CI job to pin dependencies on different platforms.

[webknjaz]

I'd like to have a solution that works with dependabot. Can't we have just a few extra files on the top level?

[webknjaz]

Also, this turned into a feature PR. We should first just make it work the same way as on master. And only then, explore remaking things on master.

[webknjaz]

dependabot/feedback#658

[greshilov]

I'd like to have a solution that works with dependabot. Can't we have just a few extra files on the top level?

Done.

[greshilov]

@webknjaz eventually, differences with the master branch are not huge. The only problem I see is that dependencies have to be pinned using python3.6. Maybe we should include a comment on that somewhere in development docs.

[webknjaz]

Lol we switched two CI systems after Travis. But nevermind, the comment not vital for this PR.

[webknjaz]

Thanks for all the effort you've put into this!

[webknjaz]

Maybe we should include a comment on that somewhere in development docs.

Do you think this could cause issues with dependabot?

[greshilov]

Maybe we should include a comment on that somewhere in development docs.

Do you think this could cause issues with dependabot?

I don't think so, but we'll see :)