converted assertion to pytest style in test status (#8769)

tests/test_status.py

@@ -7,27 +7,27 @@ from rest_framework.status import (
 
 class TestStatus(TestCase):
     def test_status_categories(self):
-        self.assertFalse(is_informational(99))
-        self.assertTrue(is_informational(100))
-        self.assertTrue(is_informational(199))
-        self.assertFalse(is_informational(200))
+        assert not is_informational(99)
+        assert is_informational(100)
+        assert is_informational(199)
+        assert not is_informational(200)
 
-        self.assertFalse(is_success(199))
-        self.assertTrue(is_success(200))
-        self.assertTrue(is_success(299))
-        self.assertFalse(is_success(300))
+        assert not is_success(199)
+        assert is_success(200)
+        assert is_success(299)
+        assert not is_success(300)
 
-        self.assertFalse(is_redirect(299))
-        self.assertTrue(is_redirect(300))
-        self.assertTrue(is_redirect(399))
-        self.assertFalse(is_redirect(400))
+        assert not is_redirect(299)
+        assert is_redirect(300)
+        assert is_redirect(399)
+        assert not is_redirect(400)
 
-        self.assertFalse(is_client_error(399))
-        self.assertTrue(is_client_error(400))
-        self.assertTrue(is_client_error(499))
-        self.assertFalse(is_client_error(500))
+        assert not is_client_error(399)
+        assert is_client_error(400)
+        assert is_client_error(499)
+        assert not is_client_error(500)
 
-        self.assertFalse(is_server_error(499))
-        self.assertTrue(is_server_error(500))
-        self.assertTrue(is_server_error(599))
-        self.assertFalse(is_server_error(600))
+        assert not is_server_error(499)
+        assert is_server_error(500)
+        assert is_server_error(599)
+        assert not is_server_error(600)