Polyfill jQuery animations with Velocity

jquery.velocity.js

// polyfill jQuery animation engine
$.fn.animate = $.fn.velocity;
$.fn.fadeTo = function (duration, opacity, complete) {
	return this.velocity({opacity: opacity}, { duration: duration, complete: complete });
};
$.fn.fadeIn = function (duration, complete) {
	return this.velocity('fadeIn', { duration: duration, complete: complete });
};
$.fn.fadeOut = function (duration, complete) {
	return this.velocity('fadeOut', { duration: duration, complete: complete });
};
$.fn.slideUp = function (duration, complete) {
	return this.velocity('slideUp', { duration: duration, complete: complete });
};
$.fn.slideDown = function (duration, complete) {
	return this.velocity('slideDown', { duration: duration, complete: complete });
};