Make useCallback hook's keys optional

[jezsung]

Makes the useCallback hook's keys property optional and default to an empty list.

[rrousselGit]

Thanks!
Could you add a test for this too? 🙏

[codecov]

Codecov Report

Patch and project coverage have no change.

Comparison is base (2a6b45c) 99.87% compared to head (3558a74) 99.87%.

❗ Current head 3558a74 differs from pull request most recent head 258b69e. Consider uploading reports for the commit 258b69e to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #369   +/-   ##
=======================================
  Coverage   99.87%   99.87%           
=======================================
  Files          18       18           
  Lines         775      775           
=======================================
  Hits          774      774           
  Misses          1        1           

Impacted Files	Coverage Δ
packages/flutter_hooks/lib/src/primitives.dart	100.00% <ø> (ø)

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[jezsung]

@rrousselGit Sure, should I also upgrade the version to 0.18.7?

[rrousselGit]

No, I bump versions myself

[rrousselGit]

LGTM, thanks!