BC: if key is set to token, the new tokenKey default will overwrite it

I realize this is very nit-picky.

Commit 9cf6a15c03948fd7b415bfa8d0c7946020b6100b adds a tokenKey that writes the raw token to the key specified. This’ll break backwards compatibility if the “key” preference is set to ‘token’ like this:

const jwt = require('koa-jwt');
jwt({ key: 'token'});

In that case, the value at token will be the user variable in versions <=1.2.0 but the raw string token in 1.3.0 >=.

[sdd]

No problem! opts.tokenKey support was only in the wild for a few days so there will be few if any users relying on that functionality. Plus the fix for those users (adding { tokenKey: 'token' }) is trivial, whereas both identifying the problem and fixing it without this PR for users like you, who are expecting ctx.state.token not to be touched, is more difficult. I can push this to npm as a patch release later today.

[sdd]

Published as v2.2.1