tokenExpiration expects seconds, not microseconds

[joecullin]

The README shows an example tokenExpiration value of 3600000, with a comment saying "1 hour."

It's sending that value to https://github.com/auth0/node-jsonwebtoken as the "maxAge" parameter. According to that module's docs (and to my own test of this module), if you pass an integer it will interpret the value as seconds.

So setting tokenExpiration to 30 will set a 30 minute maximum on the auth token.