Merge pull request jimmysong#126 from Ice101781/patch-3

Fix test_add2() for consistency with the Exercises

Author: jimmysong

code-ch02/ecc.py

@@ -202,5 +202,5 @@ def test_add1(self):
         self.assertEqual(a + b, Point(x=2, y=-5, a=5, b=7))
 
     def test_add2(self):
-        a = Point(x=-1, y=1, a=5, b=7)
-        self.assertEqual(a + a, Point(x=18, y=-77, a=5, b=7))
+        a = Point(x=-1, y=-1, a=5, b=7)
+        self.assertEqual(a + a, Point(x=18, y=77, a=5, b=7))