add github_actions_check_standard

.github/workflows/R-CMD-check.yaml

@@ -1,9 +1,13 @@
+# For help debugging build failures open an issue on the RStudio community with the 'github-actions' tag.
+# https://community.rstudio.com/new-topic?category=Package%20development&tags=github-actions
 on:
   push:
     branches:
+      - main
       - master
   pull_request:
     branches:
+      - main
       - master
 
 name: R-CMD-check
@@ -20,21 +24,22 @@ jobs:
         config:
           - {os: windows-latest, r: 'release'}
           - {os: macOS-latest, r: 'release'}
-          - {os: ubuntu-18.04, r: 'release', rspm: "https://packagemanager.rstudio.com/cran/__linux__/bionic/latest"}
-          - {os: ubuntu-18.04, r: 'devel', rspm: "https://packagemanager.rstudio.com/cran/__linux__/bionic/latest"}
+          - {os: ubuntu-20.04, r: 'release', rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest"}
+          - {os: ubuntu-20.04, r: 'devel', rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest"}
 
     env:
       R_REMOTES_NO_ERRORS_FROM_WARNINGS: true
       RSPM: ${{ matrix.config.rspm }}
+      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
 
     steps:
       - uses: actions/checkout@v2
 
-      - uses: r-lib/actions/setup-r@master
+      - uses: r-lib/actions/setup-r@v1
         with:
           r-version: ${{ matrix.config.r }}
 
-      - uses: r-lib/actions/setup-pandoc@master
+      - uses: r-lib/actions/setup-pandoc@v1
 
       - name: Query dependencies
         run: |
@@ -45,7 +50,7 @@ jobs:
 
       - name: Cache R packages
         if: runner.os != 'Windows'
-        uses: actions/cache@v1
+        uses: actions/cache@v2
         with:
           path: ${{ env.R_LIBS_USER }}
           key: ${{ runner.os }}-${{ hashFiles('.github/R-version') }}-1-${{ hashFiles('.github/depends.Rds') }}
@@ -57,7 +62,7 @@ jobs:
           while read -r cmd
           do
             eval sudo $cmd
-          done < <(Rscript -e 'cat(remotes::system_requirements("ubuntu", "18.04"), sep = "\n")')
+          done < <(Rscript -e 'writeLines(remotes::system_requirements("ubuntu", "20.04"))')
 
       - name: Install dependencies
         run: |