Fixed document height miscalculation

Fixed endLocation() calculation error that was preventing scrolling i…

…n some applications.

Fixed global undefined

Fixed UMD for webpack

Switched window back to root

Added Reduce Motion support

- Switched to `requestAnimationFrame`

- Added new init method that allows for multiple instantiations on a page
- Added `cancelScroll()` method
- Removed `data-options` feature
- A selector is now required at init

Added option to ignore links with a specific selector (useful if usin…

…g the a[href*="#"] selector option)

- Updated docs

- Fixed bug with new custom easing patterns

Removed console.log()