Add build testing

.github/workflows/docker-publish.yml

@@ -16,6 +16,10 @@ jobs:
         uses: docker/setup-qemu-action@v2
       - name: Set up Docker Buildx
         uses: docker/[email protected]
+      - name: Build
+        run: docker build -t gameservermanagers/linuxgsm:ubuntu-22.04 -f ./Dockerfile.ubuntu-2204 .
+      - name: Test
+        run: docker run --rm gameservermanagers/linuxgsm:ubuntu-22.04 ./linuxgsm.sh list
       - name: Login to DockerHub
         uses: docker/[email protected]
         with:
@@ -49,6 +53,10 @@ jobs:
         uses: docker/setup-qemu-action@v2
       - name: Set up Docker Buildx
         uses: docker/[email protected]
+      - name: Build
+        run: docker build -t gameservermanagers/linuxgsm:ubuntu-20.04 -f ./Dockerfile.ubuntu-2004 .
+      - name: Test
+        run: docker run --rm gameservermanagers/linuxgsm:ubuntu-20.04 ./linuxgsm.sh list
       - name: Login to DockerHub
         uses: docker/[email protected]
         with:
@@ -80,6 +88,10 @@ jobs:
         uses: docker/setup-qemu-action@v2
       - name: Set up Docker Buildx
         uses: docker/[email protected]
+      - name: Build
+        run: docker build -t gameservermanagers/linuxgsm:ubuntu-18.04 -f ./Dockerfile.ubuntu-1804 .
+      - name: Test
+        run: docker run --rm gameservermanagers/linuxgsm:ubuntu-18.04 ./linuxgsm.sh list
       - name: Login to DockerHub
         uses: docker/[email protected]
         with: