added test for multiplication of fractions and corresponding functionality

src/main/py/fractions.py

@@ -20,3 +20,6 @@ def addFractions(num1, denom1, num2, denom2):
         denom2 *= frac2Offset
     result_num = num1 + num2
     return reduceFraction(result_num, denom1)
+
+def multiplyFractions(num1, denom1, num2, denom2):
+    return (num1 * num2, denom1 * denom2)

src/test/py/test_fractions.py

@@ -27,6 +27,9 @@ class fractions(unittest.TestCase):
     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))
 
+    def test_multiply_fractions_1_by_2_and_1_by_2_should_be_1_by_4(self):
+        self.assertEqual(multiplyFractions(1,2,1,2), (1,4))
+
 
 if __name__ == '__main__':
     unittest.main()