archivers/R-cran-zip: updated to version 2.0.1

• removed PORTREVISION due to version bump
• add new test dependencies:
  • devel/R-cran-R6
  • devel/R-cran-covr
  • devel/R-cran-testthat
• update website URL to align with CRAN package
• no changelog provided

Generated by: portcran (0.1.9)