Added GitHub Actions CI

.github/workflows/check.yaml

@@ -0,0 +1,44 @@
+# Workflow derived from https://github.com/r-lib/actions/tree/v2/examples/check-standard.yaml
+name: R-CMD-check
+
+on:
+  push:
+    branches: [ master ]
+
+permissions: read-all
+
+jobs:
+  R-CMD-check:
+    name: ${{ matrix.config.os }} (${{ matrix.config.r }})
+
+    runs-on: ${{ matrix.config.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        config:
+          - { os: macos-latest, r: 'release' }
+          - { os: windows-latest, r: 'release' }
+          - { os: ubuntu-latest, r: 'devel', http-user-agent: 'release' }
+          - { os: ubuntu-latest, r: 'release' }
+          - { os: ubuntu-latest, r: 'oldrel-1' }
+
+    env:
+      R_KEEP_PKG_SOURCE: yes
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: r-lib/actions/setup-pandoc@v2
+      - uses: r-lib/actions/setup-r@v2
+        with:
+          r-version: ${{ matrix.config.r }}
+          http-user-agent: ${{ matrix.config.http-user-agent }}
+          use-public-rspm: true
+      - 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
+          build_args: 'c("--no-manual", "--compact-vignettes=gs+qpdf")'