Added CI setup and PR templates

.github/workflows/phpunit.yml

@@ -0,0 +1,29 @@
+name: PHPUnit
+
+on: [push]
+
+jobs:
+  phpunit:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Cancel Previous Run
+        uses: styfle/cancel-workflow-action@0.6.0
+        with:
+          access_token: ${{ github.token }}
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '7.4'
+          extensions: dom, curl, libxml, mbstring, zip, pcntl, pdo, sqlite, pdo_sqlite, gd, exif, imagick, bcmath
+          coverage: none
+
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Install Composer dependencies
+        run: composer install --ignore-platform-reqs
+
+      - name: Run tests
+        run: ./vendor/bin/phpunit