ci: run tests on github actions

.github/workflows/test.yml

@@ -0,0 +1,18 @@
+name: Test
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches: '*'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up environment
+        uses: ./.github/actions/setup
+      - name: Test
+        run: yarn test