Update the cache only when isLoading has changed.

[jbialobr]

What issue does this pull request resolve?
Fixes #520

What changes did you make?
Store the query result only when we transition from true->false in the isLoading prop.

Is there anything that requires more attention while reviewing?
No.

[ericgio]

Thanks for the PR @jbialobr! If you don't mind resolving the conflicts, I'll go ahead and merge this. Otherwise I can just make the change myself.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@bbbd9f1). Click here to learn what that means.
The diff coverage is 99.56%.

@@            Coverage Diff            @@
##             master     #521   +/-   ##
=========================================
  Coverage          ?   99.69%           
=========================================
  Files             ?       44           
  Lines             ?      658           
  Branches          ?      129           
=========================================
  Hits              ?      656           
  Misses            ?        2           
  Partials          ?        0

Impacted Files	Coverage Δ
src/utils/getMatchBounds.js	100% <ø> (ø)
src/utils/getStringLabelKey.js	100% <ø> (ø)
src/utils/isSelectable.js	100% <ø> (ø)
src/utils/getTruncatedOptions.js	100% <ø> (ø)
src/utils/warn.js	100% <ø> (ø)
src/utils/preventInputBlur.js	100% <ø> (ø)
src/utils/stripDiacritics.js	100% <100%> (ø)
src/components/TypeaheadMenu.react.js	100% <100%> (ø)
src/__tests__/helpers.js	100% <100%> (ø)
src/utils/getIsOnlyResult.js	100% <100%> (ø)
... and 33 more

---

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 bbbd9f1...5a8b80a. Read the comment docs.

[coveralls]

Coverage remained the same at 99.696% when pulling 5a8b80a on jbialobr:master into a00edaa on ericgio:master.

[jbialobr]

Conflicts resolved. I am happy I could contribute back to your project. Thanks!