shrine

Pull request #1519: Feature/SHRINE-2866

Merge in SHRINE/shrine from feature/SHRINE-2866 to feature/SHRINE2020-1218-cats-effect-upgrade

* commit '0788d165c62065672c03656280c47b9f6c27060f':
  Renamed ShrineServletContextSyntax to ShrineServletMounter and cleaned up some associated code for SHRINE-2866