React warning

[Fenopiu]

I've just downloaded to test this cool scratchcard creator, I've noticed that it give this warning in console:

lowPriorityWarning.js:37 Warning: Accessing PropTypes via the main React package is deprecated, and will be removed in React v16.0. Use the latest available v15.* prop-types package from npm instead. For info on usage, compatibility, migration and more, see https://fb.me/prop-types-docs

[Fenopiu]

I've noticed that there is a pull request (dated 12 August 2018) with the solution for this warning... could you please accept this pull request? :-)
#8