Added maximizing xor challenge.

hackerrank_topcoder/maximizing_xor/test_maximizing_xor.py

@@ -0,0 +1,15 @@
+from nose.tools import assert_equal
+
+
+class TestMaximingXor(object):
+
+    def test_maximizing_xor(self):
+        assert_equal(max_xor(10, 15), 7)
+        print('Success: test_maximizing_xor')
+
+def main():
+    test = TestMaximingXor()
+    test.test_maximizing_xor()
+
+if __name__ == '__main__':
+    main()