RemoveRandomElement = function (array, start, length)
{
    if (start === undefined) { start = 0; }
    if (length === undefined) { length = array.length; }

    var randomIndex = start + Math.floor(Math.random() * length);

    return SpliceOne(array, randomIndex);
}
Removes a random object from the given array and returns it.
Will return null if there are no array items that fall within the specified range or if there is no item for the randomly chosen index.

@function Phaser.Utils.Array.RemoveRandomElement
@since 3.0.0

@param {array} array - The array to removed a random element from.
@param {number} [start=0] - The array index to start the search from.
@param {number} [length=array.length] - Optional restriction on the number of elements to randomly select from.

@return {object} The random element that was removed, or `null` if there were no array elements that fell within the given range.