Add CI workflow for automated build and testing with Earthly

.github/workflows/ci.yml

@@ -0,0 +1,38 @@
+
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v2
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v1
+
+    - name: Cache Docker layers
+      uses: actions/cache@v2
+      with:
+        path: /tmp/.buildx-cache
+        key: ${{ runner.os }}-buildx-${{ github.sha }}
+        restore-keys: |
+          ${{ runner.os }}-buildx-
+
+    - name: Build and test with Earthly
+      uses: earthly/earthly-action@v1
+      with:
+        args: +test
+
+    - name: Build and save Docker image
+      uses: earthly/earthly-action@v1
+      with:
+        args: +buil

Earthfile

@@ -19,4 +19,5 @@ build:
     EXPOSE 8000
     ENTRYPOINT ["python"]
     CMD ["notes_app.py"]
-    SAVE IMAGE notes-app:latest
+    SAVE IMAGE notes-app:latest
+d