Fix test-matrix, mypy, and bad backport

- test-matrix.yml was intepreting 3.10 as '3.1' via float
- mypy recently removed its built-in type stubs for many
  third-party libraries so now need to install 'types-requests'
- Backport of the ELASTIC_CLIENT_APIVERSIONING test case
  included '8' instead of '7'

.ci/test-matrix.yml

@@ -1,18 +1,18 @@
 STACK_VERSION:
-  - 7.x-SNAPSHOT
+  - 7.13-SNAPSHOT
 
 TEST_SUITE:
   - platinum
 
 PYTHON_VERSION:
-  - 2.7
+  - "2.7"
-  - 3.4
+  - "3.4"
-  - 3.5
+  - "3.5"
-  - 3.6
+  - "3.6"
-  - 3.7
+  - "3.7"
-  - 3.8
+  - "3.8"
-  - 3.9
+  - "3.9"
-  - 3.10
+  - "3.10"
 
 PYTHON_CONNECTION_CLASS:
   - Urllib3HttpConnection

noxfile.py

@@ -47,7 +47,7 @@ def format(session):
 
 @nox.session()
 def lint(session):
-    session.install("flake8", "black", "mypy", "isort")
+    session.install("flake8", "black", "mypy", "isort", "types-requests")
 
     session.run("isort", "--check", "--profile=black", *SOURCE_FILES)
     session.run("black", "--target-version=py27", "--check", *SOURCE_FILES)

test_elasticsearch/test_connection.py

@@ -188,7 +188,7 @@ class TestBaseConnection(TestCase):
             conn = Connection()
             assert (
                 conn.headers["accept"]
-                == "application/vnd.elasticsearch+json;compatible-with=8"
+                == "application/vnd.elasticsearch+json;compatible-with=7"
             )
         finally:
             os.environ.pop("ELASTIC_CLIENT_APIVERSIONING")