use nightly nightly-2021-05-10

[jimexist]

Which issue does this PR close?

Closes #.

Rationale for this change

not sure of how frequently the nightly builds are bumped, just changing this to see if it'll break.

What changes are included in this PR?

Are there any user-facing changes?

[codecov-commenter]

Codecov Report

Merging #536 (3b44ae5) into master (d5bca0e) will not change coverage.
The diff coverage is n/a.

❗ Current head 3b44ae5 differs from pull request most recent head 72a3a5f. Consider uploading reports for the commit 72a3a5f to get more accurate results

@@ Coverage Diff @@## master #536 +/- ##
=======================================
Coverage 76.03% 76.03% =======================================
Files 157 157 Lines 26990 26990 =======================================
Hits 20521 20521 Misses 6469 6469 

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[alamb]

Looks good to me. Any concerns @Dandandan / @jorgecarleitao / @andygrove