Test environments

Local Ubuntu 20.04 installation (R 4.4.1)
GitHub Actions:
- Windows (release, oldrel, devel)
- MacOS (release, oldrel)
r-hub:
- Windows Server 2022, R-devel, 64 bit
- Ubuntu Linux 20.04.1 LTS, R-release, GCC
- Fedora Linux, R-devel, clang, gfortran

R CMD check results

0 errors | 0 warnings | 0 notes