test: add tests and configure CI/CD (#104)

.github/workflows/ci.yaml

@@ -0,0 +1,35 @@
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+name: ci
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node: [12, 14]
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node }}
+      - run: node --version
+      # The first installation step ensures that all of our production
+      # dependencies work on the given Node.js version, this helps us find
+      # dependencies that don't match our engines field:
+      - run: npm install --production --engine-strict --ignore-scripts --no-package-lock
+      # Clean up the production install, before installing dev/production:
+      - run: rm -rf node_modules
+      - run: npm install
+      - run: npm test
+  windows:
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 14
+      - run: npm install
+      - run: npm test