chore (ci): update action

.github/workflows/main.yml

@@ -1,65 +1,16 @@
-name: CI
+name: Docker Image CI
 
 on:
   push:
     branches: [ master ]
   pull_request:
+    branches: [ master ]
 
 jobs:
   build:
     runs-on: ubuntu-latest
+
     steps:
-      - name: Checkout
-        uses: actions/checkout@master
-
-      - name: Checkout rgbds
-        uses: actions/checkout@master
-        with:
-          path: rgbds
-          ref: v0.8.0
-          repository: gbdev/rgbds
-
-      - name: Install rgbds
-        working-directory: rgbds
-        run: |
-          sudo make install
-      - name: Remove rgbds
-        run: |
-          rm -rf rgbds
-      - name: Compare
-        if: ${{ github.repository_owner == 'pret' }}
-        run: |
-          make DEBUG=1 -j$(nproc) compare
-          if ! git diff-index --quiet HEAD --; then
-            echo 'Uncommitted changes detected:'
-            git diff-index HEAD --
-            return 1
-          fi
-      - name: Make
-        if: ${{ github.repository_owner != 'pret' }}
-        run: |
-          make -j$(nproc)
-          if ! git diff-index --quiet HEAD --; then
-            echo 'Uncommitted changes detected:'
-            git diff-index HEAD --
-            return 1
-          fi
-      - name: Checkout symbols
-        if: ${{ github.event_name == 'push' && github.repository_owner == 'pret' }}
-        uses: actions/checkout@master
-        with:
-          path: symbols
-          ref: symbols
-
-      - name: Move symbols
-        if: ${{ github.event_name == 'push' && github.repository_owner == 'pret' }}
-        run: |
-          cp -v *.sym symbols/
-      - name: Update symbols
-        if: ${{ github.event_name == 'push' && github.repository_owner == 'pret' }}
-        uses: EndBug/add-and-commit@v7
-        with:
-          branch: symbols
-          cwd: "./symbols"
-          add: "*.sym"
-          message: ${{ github.event.commits[0].message }}
+    - uses: actions/checkout@v2
+    - name: Build the Docker image
+      run: docker build . --file Dockerfile --tag my-image-name:$(date +%s)