Update status code docs (encode#6732)

Author: rpkilby

docs/api-guide/status-codes.md

@@ -20,13 +20,13 @@ The full set of HTTP status codes included in the `status` module is listed belo
 The module also includes a set of helper functions for testing if a status code is in a given range.
 
  from rest_framework import status
-from rest_framework.test import APITestCase
+ from rest_framework.test import APITestCase
 
-class ExampleTestCase(APITestCase):
- def test_url_root(self):
- url = reverse('index')
- response = self.client.get(url)
- self.assertTrue(status.is_success(response.status_code))
+ class ExampleTestCase(APITestCase):
+  def test_url_root(self):
+  url = reverse('index')
+  response = self.client.get(url)
+  self.assertTrue(status.is_success(response.status_code))
 
 
 For more information on proper usage of HTTP status codes see [RFC 2616][rfc2616]
@@ -51,6 +51,8 @@ This class of status code indicates that the client's request was successfully r
  HTTP_205_RESET_CONTENT
  HTTP_206_PARTIAL_CONTENT
  HTTP_207_MULTI_STATUS
+ HTTP_208_ALREADY_REPORTED
+ HTTP_226_IM_USED
 
 ## Redirection - 3xx
 
@@ -64,6 +66,7 @@ This class of status code indicates that further action needs to be taken by the
  HTTP_305_USE_PROXY
  HTTP_306_RESERVED
  HTTP_307_TEMPORARY_REDIRECT
+ HTTP_308_PERMANENT_REDIRECT
 
 ## Client Error - 4xx
 
@@ -90,6 +93,7 @@ The 4xx class of status code is intended for cases in which the client seems to
  HTTP_422_UNPROCESSABLE_ENTITY
  HTTP_423_LOCKED
  HTTP_424_FAILED_DEPENDENCY
+ HTTP_426_UPGRADE_REQUIRED
  HTTP_428_PRECONDITION_REQUIRED
  HTTP_429_TOO_MANY_REQUESTS
  HTTP_431_REQUEST_HEADER_FIELDS_TOO_LARGE
@@ -105,7 +109,11 @@ Response status codes beginning with the digit "5" indicate cases in which the s
  HTTP_503_SERVICE_UNAVAILABLE
  HTTP_504_GATEWAY_TIMEOUT
  HTTP_505_HTTP_VERSION_NOT_SUPPORTED
+ HTTP_506_VARIANT_ALSO_NEGOTIATES
  HTTP_507_INSUFFICIENT_STORAGE
+ HTTP_508_LOOP_DETECTED
+ HTTP_509_BANDWIDTH_LIMIT_EXCEEDED
+ HTTP_510_NOT_EXTENDED
  HTTP_511_NETWORK_AUTHENTICATION_REQUIRED
 
 ## Helper functions