one thing that I find weird on the current swipe method is that it only works in one direction.. so I think we should rename it to `swipeForward`, `swipeToLeft`, ... (something that makes it clear the direction of the movement).

maybe create a private `_flick(element, startRatioX, endRatioX)` (where ratio is a value between 0-1) so you could implement as:

```js
function swipeLeft(el) {
  this._flick(el, 0.2, 0);
  return this;
}

function swipeRight(el) {
  this._flick(el, 0.8, 0.6);
  return this;
}
```