Add GitHub Actions workflow

Author: sheepsteak

.github/workflows/main.yml

@@ -0,0 +1,22 @@
+name: CI
+
+on: [push]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - uses: docker://node:8
+        with:
+          entrypoint: yarn
+          args: install --pure-lockfile --audit
+      - uses: docker://node:8
+        with:
+          entrypoint: yarn
+          args: lint
+      - uses: docker://node:8
+        with:
+          entrypoint: yarn
+          args: test