Updating Github workflow

Author: dbetebenner

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

@@ -1,5 +1,3 @@
-# Workflow derived from https://github.com/r-lib/actions/tree/v2/examples
-# Need help debugging build failures? Start at https://github.com/r-lib/actions#where-to-find-help
 on:
   push:
     branches: [main, master]
@@ -20,7 +18,7 @@ jobs:
         config:
           - {os: macos-latest,   r: 'release'}
           - {os: windows-latest, r: 'release'}
-          - {os: ubuntu-latest,   r: 'devel', http-user-agent: 'release'}
+          - {os: ubuntu-latest,   r: 'devel'}
           - {os: ubuntu-latest,   r: 'release'}
           - {os: ubuntu-latest,   r: 'oldrel-1'}
 
@@ -49,11 +47,19 @@ jobs:
           http-user-agent: ${{ matrix.config.http-user-agent }}
           use-public-rspm: true
 
+      # Cache R packages to speed up builds
+      - name: Cache R packages
+        uses: actions/cache@v3
+        with:
+          path: ~/.cache/R
+          key: ${{ runner.os }}-r-${{ matrix.config.r }}-${{ hashFiles('**/DESCRIPTION') }}
+          restore-keys: ${{ runner.os }}-r-${{ matrix.config.r }}
+
       - uses: r-lib/actions/setup-r-dependencies@v2
         with:
           extra-packages: any::rcmdcheck
           needs: check
 
       - uses: r-lib/actions/check-r-package@v2
         with:
-          upload-snapshots: true
+          upload-snapshots: true