add keepat!

[bkamins]

Fixes #750

[codecov]

Codecov Report

Merging #770 (264c6e1) into master (4e631e6) will increase coverage by 0.72%.
The diff coverage is 92.85%.

@@            Coverage Diff             @@
##           master     #770      +/-   ##
==========================================
+ Coverage   88.35%   89.08%   +0.72%     
==========================================
  Files           2        2              
  Lines         146      174      +28     
==========================================
+ Hits          129      155      +26     
- Misses         17       19       +2     

Impacted Files	Coverage Δ
src/Compat.jl	89.54% <92.85%> (+0.74%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 4e631e6...264c6e1. Read the comment docs.

[martinholters]

LGTM (modulo adding the requested comment), but needs a rebase.

[bkamins]

but needs a rebase.

@martinholters - let us discuss how to handle the following issue.

DataFrames.jl has support back to Julia 1.0. Therefore we need this PR both in 4.0 and 3.x branches of Compat.jl. How would you like me to handle this? Thank you!

[bkamins]

I have rebased the PR. Following the discussion in #767 after this PR is merged it should be backported to 3.x branch and both 3.x. and 4.x. releases should be done. Thank you!

[martinholters]

Given that 4.0.0 has been yanked, should this be 4.0.1? @KristofferC?

[martinholters]

Are we ok with merging and tagging this as 4.1.0? @KristofferC?

[bkamins]

Thank you!

How do we go about now to making a backport of this PR to 3.x branch and making a release?

[martinholters]

You create a branch off of release-3, backport this change (git cherry-pick -x cad170038b8c63ba8c4b37c7cba62455bba4c368), amend the version in Project.toml and README.md to 3.44, open a PR against againt release-3. Once that is merged, we tag as usual.