Update requests/urllib3 dependency and allow retries on our POST requests

Author: leszekhanusz

gql/transport/requests.py

@@ -95,6 +95,7 @@ def connect(self):
                         total=self.retries,
                         backoff_factor=0.1,
                         status_forcelist=[500, 502, 503, 504],
+                        allowed_methods=None,
                     )
                 )
                 for prefix in "http://", "https://":

setup.py

@@ -37,8 +37,9 @@
 ]
 
 install_requests_requires = [
-    "requests>=2.23,<3",
+    "requests>=2.26,<3",
     "requests_toolbelt>=0.9.1,<1",
+    "urllib3>=1.26",
 ]
 
 install_websockets_requires = [