Removing duplicates from a list

Question Q4.2.2

Write a function, using set objects, to remove duplicates from an ordered list. For example,

>>> remove_dupes([1,1,2,3,4,4,4,5,7,8,8,9])
[1, 2, 3, 4, 5, 7, 8, 9]

Solution Q4.2.2