The Ractive equivalent to
Array.pop that removes an element from the end of the array at the given keypath and triggers an update event.
ractive.pop( keypath )
Promise(see Promises) that will resolve with the removed element after the update is complete.
The keypath of the array to change, e.g.
If the given keypath does not exist (is
undefined), an empty array will be supplied instead. Otherwise, if the given keypath does not resolve to an array, an error will be thrown.