add type stub packages

requirements/typing.txt

@@ -4,11 +4,21 @@
 #
 #    pip-compile requirements/typing.in
 #
+cffi==1.14.6
+    # via cryptography
+cryptography==3.4.7
+    # via -r requirements/typing.in
 mypy==0.910
     # via -r requirements/typing.in
 mypy-extensions==0.4.3
     # via mypy
+pycparser==2.20
+    # via cffi
 toml==0.10.2
     # via mypy
+types-dataclasses==0.1.7
+    # via -r requirements/typing.in
+types-setuptools==57.0.2
+    # via -r requirements/typing.in
 typing-extensions==3.10.0.0
     # via mypy