Leading plus character is considered an error

[Enrico204]

By the ISO 8601, years after and including 0000 may be prefixed with the plus sign +. E.g., +2007-00-00T00:00:00Z is a valid date.

Trying to parse the date using this library results in a UnexpectedCharactError.

This problem occurs with v1.1.0. I wasn't able to test the v2.0.0 (due to known problem with go.mod).

[relvacode]

Released in https://github.com/relvacode/iso8601/releases/tag/v1.3.0

V2 has also been dropped, future versions will remain on v1

[Enrico204]

Thanks!