added another testcase for addition where the result needs to be reduced and updated the code accordingly

src/main/py/fractions.py

@@ -19,4 +19,4 @@ def addFractions(num1, denom1, num2, denom2):
         num2 *= frac2Offset
         denom2 *= frac2Offset
     result_num = num1 + num2
-    return (result_num, denom1)
+    return reduceFraction(result_num, denom1)

src/test/py/test_fractions.py

@@ -24,6 +24,9 @@ class fractions(unittest.TestCase):
     def test_add_fractions_1_by_10_and_1_by_5_should_be_3_by_10(self):
         self.assertEqual(addFractions(1,10,1,5), (3,10))
 
+    def test_add_fractions_1_by_10_and_2_by_5_should_be_1_by_2(self):
+        self.assertEqual(addFractions(1, 10, 2, 5), (1, 2))
+
 
 if __name__ == '__main__':
     unittest.main()