Switch to AtomicPut in Create methods

[mthenw]

Todos:

• Write tests
• Write documentation
• Fix linting errors
• Make sure code coverage hasn't dropped
• Provide verification commands / resources
• Enable "Allow edits from maintainers" for this PR
• Update the messages below

Is this ready for review?: YES
Is it a breaking change?: NO

[codecov]

Codecov Report

Merging #457 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master     #457   +/-   ##
=======================================
  Coverage   66.17%   66.17%           
=======================================
  Files          32       32           
  Lines        1892     1892           
=======================================
  Hits         1252     1252           
  Misses        587      587           
  Partials       53       53

Impacted Files	Coverage Δ
libkv/subscription.go	88.02% <100%> (ø)	⬆️
libkv/function.go	84.81% <100%> (ø)	⬆️
libkv/eventtype.go	85.71% <100%> (ø)	⬆️

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