This commit serves as the basis for further `v5` developments. It will introduce some API-breaking changes, especially to the way tokens are validated. This will allow us to provide some long-wanted features with regards to the validation API. We are aiming to do this as smoothly as possible, however, with any major version. please expect that you might need to adapt your code.
The actual development will be done in the course of the next week, if time permits. It will be done in seperate PRs that will use this PR as a base. Afterwards, we will probably merge this and release an initial 5.0.0-alpha1 or similar.
This PR aims at implementing compliance to RFC7519, as documented in #11 without breaking the public API. It creates a new struct `RegisteredClaims` and deprecates (but not removes) the `StandardClaims`. It introduces a new type `NumericDate`, which represents a JSON numeric date value as specified in the RFC. This allows us to handle float as well as int-based time fields in `aud`, `exp` and `nbf`. Additionally, it introduces the type `StringArray`, which is basically a wrapper around `[]string` to deal with the oddities of the JWT `aud` field.
Christian Banse