Make mypy configuration stricter and improve typing (#830)

* PyJWS._verify_signature: raise early KeyError if header is missing alg

* Make Mypy configuration stricter

* Improve typing in jwt.utils

* Improve typing in jwt.help

* Improve typing in jwt.exceptions

* Improve typing in jwt.api_jwk

* Improve typing in jwt.api_jws

* Improve typing & clean up imports in jwt.algorithms

* Correct JWS.decode rettype to any (payload could be something else)

* Update typing in api_jwt

* Improve typing in jwks_client

* Improve typing in docs/conf.py

* Fix (benign) mistyping in test_advisory

* Fix misc type complaints in tests

1 files changed, 2 insertions, 2 deletions

diff --git a/docs/conf.py b/docs/conf.py
index 44b5103..938631f 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -4,7 +4,7 @@ import re
 import sphinx_rtd_theme
 
 
-def read(*parts):
+def read(*parts) -> str:
     """
     Build an absolute path from *parts* and and return the contents of the
     resulting file.  Assume UTF-8 encoding.
@@ -14,7 +14,7 @@ def read(*parts):
         return f.read()
 
 
-def find_version(*file_paths):
+def find_version(*file_paths) -> str:
     """
     Build a path from *file_paths* and search for a ``__version__``
     string inside.