TypeError when token is not a string

[ricardogama]

I started getting uncaught exceptions when receiving tokens that are not strings:

TypeError: jwtString.split is not a function

Since I'm only handling errors exposed by this library I expected a JsonWebTokenError to be thrown when verifying a value other than string.

I saw some issues related to this error but the focus was on throwing or return it on the callback. This way I suggest to test the type of the token before splitting it and throw a JsonWebTokenError if not a string.