Sanctioning authors not parsed

Fungal names often have a sanctioning author (Fr. or Pers.) following a colon after the basionym or combination authorship. This is currently unparsed.

Example: Boletus versicolor L. : Fr. ICNfap Article 50: http://www.iapt-taxon.org/nomen/main.php?page=r50E&emph=sanctioned https://en.wikipedia.org/wiki/Sanctioned_name

https://github.com/GlobalNamesArchitecture/gnparser/issues/409