BREAKING CHANGES:

* Minimum supported Ruby version bumped from 2.5 to 2.7.

FIXED:

* PINs with future birthdates are now parsed as long as they are for the
  current year.
    * Example: `20xyab-nnnn` used to be parsed as `1920` until `2020-xy-ab`,
    but now it's parsed as `2020` from 2020-01-01 and onwards. This is more
    correct, since all 1920s PINs should be written with a `+` after
    2020-01-01.
* Parsing of 10-digit PINs were improved so it is always consistent so
  `parse(pin.to_s(10)) == pin`.

REMOVED:

* Explicit installation of `rake` and `minitest` as development dependencies
  removed. Now relying on the versions bundled with Ruby.