Fix jsonwebtoken is not a dev dependency

[simov]

Obviously 1.5.0 is broken.

[simov]

Ok, I'll expand a little bit on this:

Since you published v1.5.0 a few days ago, your module now depends on jsonwebtoken because of the new passport integration. Your published module depends on jsonwebtoken, not your test suite.

Unless the consumer of this module have explicit dependency on jsonwebtoken or some of its other dependencies happens to have it installed under the root of the node_modules folder, their code will fail, because of the missing jsonwebtoken dependency required in the passport integration.

Hope that makes sense.