Export Parser and test

[jkevlin2]

In order to get access to the key id in the header for a key lookup, it would be helpful to have access to the parser.

Addresses issue #39

[coveralls]

Coverage remained the same at 100.0% when pulling 399fee9 on jkevlin:issues/39 into e5ade5a on jwtk:master.

[jkevlin2]

I submitted the changes, but I couldn't wait, so I had to fork the repo and push the changes there. https://github.com/nodeaholic/jwt-node Subject: Re: [jwtk/njwt] Export Parser and test (#40) +1. Would love for this to be built-in functionality instead of having to manually import source files.

[eszjay]

This looks super useful! I'd love to be able to use the parser to read elements from the token prior to verification.