Add solution for leetcode containsDuplicate

Author: wisdom08

contains-duplicate/wisdom08.py

@@ -0,0 +1,7 @@
+class Solution(object):
+    def containsDuplicate(self, nums):
+        set_nums = set(nums)
+        if len(nums) == len(set_nums):
+            return False
+        else:
+            return True