Write a function remove_duplicates that takes in a list and removes elements of the list that are the same.

For example: remove_duplicates([1, 1, 2, 2]) should return [1, 2].

• Don’t remove every occurrence, since you need to keep a single occurrence of a number.
• The order in which you present your output does not matter. So returning [1, 2, 3] is the same as returning [3, 1, 2].
• Do not modify the list you take as input! Instead, return a new list.