Merge remote-tracking branch 'origin/master'

# Conflicts:
#	.github/workflows/GitHub_Actions_CI.yaml

Author: RLumSK

.github/workflows/GitHub_Actions_CI.yaml

@@ -23,11 +23,11 @@ jobs:
         config:
           - {os: macOS-latest,   r: 'release'}
           - {os: macOS-latest,   r: 'oldrel'}
-          - {os: ubuntu-20.04,   r: 'devel', rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest", http-user-agent: "R/4.2.0 (ubuntu-20.04) R (4.2.0 x86_64-pc-linux-gnu x86_64 linux-gnu) on GitHub Actions" }
-          - {os: ubuntu-20.04,   r: 'release', rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest"}
-          - {os: ubuntu-18.04,   r: 'oldrel',  rspm: "https://packagemanager.rstudio.com/cran/__linux__/bionic/latest"}
+          - {os: ubuntu-16.04,   r: 'devel', rspm: "https://packagemanager.rstudio.com/cran/__linux__/xenial/latest", http-user-agent: "R/4.0.0 (ubuntu-16.04) R (4.0.0 x86_64-pc-linux-gnu x86_64 linux-gnu) on GitHub Actions" }
+          - {os: ubuntu-16.04,   r: 'release', rspm: "https://packagemanager.rstudio.com/cran/__linux__/xenial/latest"}
+          - {os: ubuntu-16.04,   r: 'oldrel',  rspm: "https://packagemanager.rstudio.com/cran/__linux__/xenial/latest"}
           - {os: windows-latest,  r: 'devel'}
-          - {os: windows-latest, r: 'release'}
+          - {os: windows-latest,  r: 'release'}
           - {os: windows-latest,  r: 'oldrel'}
 
     env: