Warning: Maximum update depth exceeded.

[flash716]

I am seeing the following error in the console when using Marquee.

react_devtools_backend.js:2430 Warning: Maximum update depth exceeded. This can happen when a component calls setState inside useEffect, but useEffect either doesn't have a dependency array, or one of the dependencies changes on every render.
    at Marquee (http://localhost:1212/dist/renderer.dev.js:315289:17)

I believe the first useEffect (the one that calls calculateWidth) should have an empty dependency array. Without it the effect is continually running since calculateWidth changes state every time it runs.

Let me know if you would like a PR for this.

[justin-chu]

Should be fixed by #48