In the previous challenge, we learned about each method being central to all
of the methods provided by Enumerable class. One of such useful methods is
each_with_index which allows you to iterate over items along with an index
keeping count of the item.
For example,
> colors = ['red', 'green', 'blue']
> colors.each_with_index { |item, index| p "#{index}:#{item}" }
"0:red"
"1:green"
"2:blue"
As you can note, the counting of items starts from 0.
In this challenge, your task is to complete the skip_animals method that
takes an animals array and a skip integer and returns an array of all elements  except first skip number of items as shown in the example below.  
For example,
> skip_animals(['leopard', 'bear', 'fox', 'wolf'], 2)
=> ["2:fox", "3:wolf"]
It is guaranteed that number of items in animals array is greater than the
value of skip.