Add tests to GitHub Actions configuration

Author: remram44

.github/workflows/test.yml

@@ -16,3 +16,17 @@ jobs:
         chmod +x /usr/local/bin/tidy
     - name: Validate HTML
       run: tidy -errors -quiet --drop-empty-elements no regex.html
+
+  test_sed:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Run sed tests
+      run: tests/test_sed.sh
+
+  set_vim:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Run Vim tests
+      run: tests/test_vim.sh