Typo in auth/jwt package

[amidam]

I have noticed a typo which was repeated a couple of times in auth/jwt package.
As JWT stands for JSON Web Token, so the Token after JWT is somehow redundant.
I was wondering if you are OK to revise all of the occurrences of JWT Token to JWT?
This change also includes the revision of JWTTokenContextKey to JWTContextKey.

[sagikazarmark]

Fixed in #1070