Migrate from CircleCI to GitHub Actions

.github/workflows/build.yml

@@ -0,0 +1,61 @@
+name: build
+
+on: push
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.7
+
+      - name: Install dependencies
+        run: |
+            pip install virtualenv
+            virtualenv venv
+            source venv/bin/activate
+            pip install .[dev]
+
+      - name: Check formatting
+        run: |
+            source venv/bin/activate
+            ./scripts/check_format.sh
+
+      - name: Lint
+        run: |
+          source venv/bin/activate
+          flake8 datadog_lambda/
+
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      max-parallel: 4
+      matrix:
+        python-version: [2.7, 3.6, 3.7, 3.8]
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install dependencies
+        run: |
+          pip install virtualenv
+          virtualenv venv
+          source venv/bin/activate
+          pip install .[dev]
+
+      - name: Run tests
+        run: |
+          source venv/bin/activate
+          nose2 -v

README.md

@@ -1,6 +1,6 @@
 # datadog-lambda-python
 
-[![CircleCI](https://img.shields.io/circleci/build/github/DataDog/datadog-lambda-python)](https://circleci.com/gh/DataDog/datadog-lambda-python)
+![build](https://github.com/DataDog/datadog-lambda-python/workflows/build/badge.svg)
 [![PyPI](https://img.shields.io/pypi/v/datadog-lambda)](https://pypi.org/project/datadog-lambda/)
 ![PyPI - Python Version](https://img.shields.io/pypi/pyversions/datadog-lambda)
 [![Slack](https://img.shields.io/badge/slack-%23serverless-blueviolet?logo=slack)](https://datadoghq.slack.com/channels/serverless/)