Write a function that takes in a list of numbers. The function should return a new list of those items, in the same order, but with any duplicates removed.
For example:
>>> remove_dupes([5, 5, 5])
[5]
>>> remove_dupes([1, 4, 1, 1, 3])
[1, 4, 3]
>>> remove_dupes([8, 11, 9])
[8, 11, 9]