added test case for test_limit (#819)

Author: Bogyie

tests/test_array.py

@@ -385,6 +385,7 @@ def test_top_1(self):
 class TestLimit(unittest.TestCase):
 
     def test_limit(self):
+        self.assertListEqual(limit([1, 2, 3, 4, 5]), [1, 2, 3, 4, 5])
         self.assertListEqual(limit([1, 2, 3, 4, 5], 2, 4), [2, 3, 4])
         self.assertListEqual(limit([1, 2, 3, 4, 5], 2), [2, 3, 4, 5])
         self.assertListEqual(limit([1, 2, 3, 4, 5], None, 4), [1, 2, 3, 4])