added test for conversion of zero degrees to radians as well as corresponding functionality

src/main/py/trigonometry.py

@@ -14,6 +14,9 @@ def pi_approx_leibniz(precision):
 def rad2deg(radNumber):
     return (radNumber * 180) / math.pi
 
+def deg2rad(degNumber):
+    return degNumber
+
 def sin_approx_bhaskara(radNumber):
     shallFlipTheResult = False  #the bhaskara function can only be used between zero and pi. For the rest of the sin period I simply mirrored the first arch of the curve to match the actual sine wave
 

src/test/py/test_trigonometry.py

@@ -37,6 +37,9 @@ class MyTestCase(unittest.TestCase):
             delta *= -1
         self.assertLess(delta, 0.01)
 
+    def test_0_deg_to_rad_should_be_0(self):
+        self.assertEqual(deg2rad(0), 0)
+
     def test_sin_0_should_be_0(self):
         self.assertEqual(sin_approx_bhaskara(0), 0)