Migrate to github actions

.github/workflows/ci.yml

@@ -0,0 +1,26 @@
+name: CI
+
+on: [push]
+
+env:
+  CI: true
+
+jobs:
+  Test:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        channel: [stable, beta]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions/setup-ruby@v1
+        with:
+          ruby-version: '2.6'
+      - uses: actions/setup-node@v2
+        with:
+          node-version: '14'
+      - name: Build
+        run: |
+          npm install
+          script/cibuild