feat: add 7.x source code

.github/workflows/continuous_integration.yml

@@ -0,0 +1,43 @@
+name: Continuous Integration
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@v2
+      - name: Run linters
+        uses: golangci/golangci-lint-action@v2
+        with:
+          version: v1.39
+
+  tests:
+    needs:
+      - Lint
+    name: Tests
+    # TODO: once arm64 actions are available, also run the tests on this architecture.
+    # See: https://github.com/actions/virtual-environments/issues/2552#issuecomment-771478000.
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Checkout source code
+        uses: actions/checkout@v2
+      - name: Build testing environment
+        run: make build build-tests
+      - name: Run tests
+        run: |
+          make tests-once
+          bash <(curl -s https://codecov.io/bash)