Package check result: NOTE

Check: CRAN incoming feasibility, Result: NOTE
  Maintainer: ‘Ben Goodrich <benjamin.goodrich@columbia.edu>’
  
  Found the following (possibly) invalid URLs:
    URL: https://sites.stat.columbia.edu/gelman/arm/
      From: inst/doc/binomial.html
            inst/doc/continuous.html
            inst/doc/count.html
      Status: Error
      Message: SSL peer certificate or SSH remote key was not OK [sites.stat.columbia.edu]:
        server verification failed: certificate signer not trusted. (CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none)
    URL: https://stat.columbia.edu/~gelman/arm/
      From: man/rstanarm-datasets.Rd
            man/rstanarm-package.Rd
      Status: Error
      Message: SSL peer certificate or SSH remote key was not OK [sites.stat.columbia.edu]:
        server verification failed: certificate signer not trusted. (CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none)
    URL: https://stat.columbia.edu/~gelman/book/
      From: man/priors.Rd
            man/rstanarm-package.Rd
      Status: Error
      Message: SSL peer certificate or SSH remote key was not OK [sites.stat.columbia.edu]:
        server verification failed: certificate signer not trusted. (CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none)
    URL: https://www.stat.columbia.edu/~gelman/book/data/rats.asc
      From: inst/doc/pooling.html
      Status: Error
      Message: SSL peer certificate or SSH remote key was not OK [sites.stat.columbia.edu]:
        server verification failed: certificate signer not trusted. (CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none)