Change componentWillReceiveProps to componentDidUpdate

[kaelxeth]

#149

Because componentWillReceiveProps will be deprecated soon, changes made is based on Dan Abramov's statement at reactjs/react.dev#721

That’s the exact use case for componentDidUpdate and it’s more accurate than componentWillReceiveProps because it only fires when the prop has actually changed

[codecov]

Codecov Report

Merging #149 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master    #149   +/-   ##
======================================
  Coverage    89.1%   89.1%           
======================================
  Files           4       4           
  Lines         101     101           
  Branches       25      25           
======================================
  Hits           90      90           
  Misses          9       9           
  Partials        2       2

Impacted Files	Coverage Δ
src/with-size.js	95% <100%> (ø)	⬆️

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[ctrlplusb]

Thanks 👍