How to use
Create a new Walkway instance with a supplied options object. When you want to start animating call .draw on the returned instance providing an optional callback that will be called when drawing is complete.
selector (mandatory) – The selector of the parent element (usually will be a specific svg element)
duration – Time the animation should run for, in ms. Default is 400.
easing – Name of the easing function used for drawing. Default is ‘easeInOutCubic’. You can also supply your own function that will be passed the progress and should return a value in the range of [0, 1];