Package check result: NOTE

Check: CRAN incoming feasibility, Result: NOTE
  Maintainer: ‘Ioannis Kosmidis <ioannis.kosmidis@warwick.ac.uk>’
  
  Found the following (possibly) invalid URLs:
    URL: https://www.gnu.org/licenses/gpl-3.0.html
      From: README.md
      Status: Error
      Message: Could not connect to server [www.gnu.org]:
        Failed to connect to www.gnu.org port 443 after 489 ms: Could not connect to server

No changes to worse in reverse depends.