Added hanoi challenge.

stacks_queues/hanoi/test_hanoi.py

@@ -0,0 +1,38 @@
+from nose.tools import assert_equal
+
+
+class TestHanoi(object):
+    
+    def test_hanoi(self):
+        num_disks = 3
+        src = Stack()
+        buff = Stack()
+        dest = Stack()
+
+        print('Test: NULL towers')
+        hanoi(num_disks, None, None, None)
+
+        print('Test: 0 disks')
+        hanoi(num_disks, src, dest, buff)
+        assert_equal(dest.pop(), None)
+
+        print('Test: 1 disk')
+        src.push(5)
+        hanoi(num_disks, src, dest, buff)
+        assert_equal(dest.pop(), 5)
+
+        print('Test: 2 or more disks')
+        for i in xrange(num_disks, -1, -1):
+            src.push(i)
+        hanoi(num_disks, src, dest, buff)
+        for i in xrange(0, num_disks):
+            assert_equal(dest.pop(), i)
+
+        print('Success: test_hanoi')
+
+def main():
+    test = TestHanoi()
+    test.test_hanoi()
+    
+if __name__ == '__main__':
+    main()