Merge pull request #2 from AhmedSoliman/master

preparing the project for publish
Merge pull request #3 from AhmedSoliman/master

modified readme
Allow encoding/decoding without secret, and with algorith as 'none'

This allows the library to be used when decoding token_id responses from the Windows graph api
Merge pull request #4 from hughsimpson/master

Allow encoding/decoding without secret, and with algorith as 'none'
fixed non-exhaustive pattern match