Create climbing-stairs.py

Uses dynamic programming to work out this is essentially the fibbonacci sequence, then computes as such

climbing-stairs.py

@@ -0,0 +1,13 @@
+import math
+class Solution(object):
+    def climbStairs(self, n):
+        """
+        :type n: int
+        :rtype: int
+        """
+        l, r = 1, 1
+        for i in range(n):
+            temp = l + r
+            l = r
+            r = temp
+        return l