Run tests on push using GitHub Actions

This adds a basic CI pipeline to the repository which runs tests on
all branch pushes.

Author: hughsk-canva

.github/workflows/push.yml

@@ -0,0 +1,16 @@
+name: Push
+on:
+  push:
+    branches: "*"
+
+jobs:
+  tests:
+    name: Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 18
+      - run: npm ci
+      - run: npm test