v1.2.13

v1.2.13 07 Dec 2021
[New Features]
  * `jwt` package now has a `Builder` that may make it easier to programmatically
    create a JWT for some users.
  * `jwt` errors now can be distinguished between validation errors and others.
    Use `jwt.IsValidationError()` to check if it's a validation error, and then
    use `errors.Is()` to check if it's one of the known (oft-used) errors