test: Unpack request's return value.

Makes test a bit more readable by naming what each value is.

caucase/test.py

@@ -1667,14 +1667,14 @@ class CaucaseTest(unittest.TestCase):
       server_name,
       server_https_port,
     )
-    root_hateoas_request = request({
+    status, _, header_dict, body = request({
       'SCRIPT_NAME': '/base/path',
       'REQUEST_METHOD': 'GET',
     })
     self.maxDiff = None
-    self.assertEqual(root_hateoas_request[0], 200)
-    self.assertEqual(root_hateoas_request[2]['Content-Type'], 'application/hal+json')
-    self.assertEqual(json.loads(root_hateoas_request[3]), {
+    self.assertEqual(status, 200)
+    self.assertEqual(header_dict['Content-Type'], 'application/hal+json')
+    self.assertEqual(json.loads(body), {
       u"_links": {
         u"getCAUHAL": {
           u"href": HATEOAS_HTTP_PREFIX + u"/cau",
@@ -1689,14 +1689,14 @@ class CaucaseTest(unittest.TestCase):
         },
       },
     })
-    cau_hateoas_request = request({
+    status, _, header_dict, body = request({
       'SCRIPT_NAME': '/base/path',
       'PATH_INFO': '/cau/',
       'REQUEST_METHOD': 'GET',
     })
-    self.assertEqual(cau_hateoas_request[0], 200)
-    self.assertEqual(cau_hateoas_request[2]['Content-Type'], 'application/hal+json')
-    self.assertEqual(json.loads(cau_hateoas_request[3]), {
+    self.assertEqual(status, 200)
+    self.assertEqual(header_dict['Content-Type'], 'application/hal+json')
+    self.assertEqual(json.loads(body), {
       u"_actions": {
         u"createCertificate": {
           u"href": HATEOAS_HTTPS_PREFIX + u"/cau/crt/{+crt_id}",