Add failure notifications to Discord

Author: nicekiwi

.github/workflows/php.yml

@@ -42,4 +42,12 @@ jobs:
       - name: PHP ${{ matrix.php }} - Run coverage test suite
         env:
           apiKey: ${{ secrets.STEAM_API_KEY }}
-        run: composer run-script test
+        run: composer run-script test
+
+      - uses: sarisia/actions-status-discord@v1
+        if: ${{ failure() }}
+        with:
+          status: ${{ job.status }}
+          webhook: ${{ secrets.DISCORD_WEBHOOK }}
+          title: "${{ matrix.php }}: Tests failed."
+          color: 'red'