• Allow the Host configuration directive and the GEOIPUPDATE_HOST
  environment variable to accept a value with the scheme set. If not set, it
  will continue to default to https://. Pull request by Gabe Cook. GitHub
  #310.
• Export HTTPError to enable fine-grained error handling for users of
  github.com/maxmind/geoipupdate/client. Pull request by Ryan Davis. GitHub
  #341.