remove travis and fix ubuntu version

.github/workflows/image.yml

@@ -9,13 +9,18 @@ on:
       - "v*"
 
 jobs:
-  build:
-    runs-on: ubuntu-latest
+  test:
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout the code
         uses: actions/checkout@v2
-      - name: Test
+      - name: Test Bash scripts
         run: sudo apt-get -qq update && sudo apt-get install -y devscripts shellcheck && make test
+  build:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout the code
+        uses: actions/checkout@v2
       # https://github.com/docker/setup-qemu-action
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v1