v3.0.0

No API-changes, but important bug fix of D-number validation. Some D-numbers that previously validated does not now, and some that previously did not validate do now (see also #30 (comment)). Thats the reason for new major version.

The actual fix was this commit: 7e4f153#diff-f41e9d04a45c83f3b6f6e630f10117fe

See Forskrift til folkeregisterloven, paragraph § 2-2-2 for more details on D-number.