Offscreen Canvas Gifler

Standalone library to render gif frames to an offscreen canvas

#### Usage
``
const gifler = new OffscreenCanvasGifler();
gifler.init('https://media.giphy.com/media/3osxY7MLrs5wP2wRgc/giphy.gif').then(() => {
gifler.setCanvasEl('#myCanvas');
gifler.animate();
});

``