ci: add GitHub Actions workflow for automated testing

- Run tests on Python 3.11 and 3.12
- Check code quality with ruff and black
- Upload coverage to Codecov
- Build and upload distribution artifacts

Author: Administrator

.github/workflows/ci.yml

@@ -0,0 +1,68 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.11', '3.12']
+
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+    
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -e ".[test]"
+    
+    - name: Run linters
+      run: |
+        pip install ruff black mypy
+        ruff check .
+        black --check .
+    
+    - name: Run unit tests
+      run: |
+        pytest tests/unit -v --cov=amazon_ads_api --cov-report=xml
+    
+    - name: Upload coverage
+      uses: codecov/codecov-action@v4
+      with:
+        files: ./coverage.xml
+        flags: unittests
+        name: codecov-umbrella
+
+  build:
+    runs-on: ubuntu-latest
+    needs: test
+    
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.11'
+    
+    - name: Build package
+      run: |
+        pip install build
+        python -m build
+    
+    - name: Upload artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: dist
+        path: dist/
+