Migrate to Github Actions (#402)

Author: benmccann

.github/workflows/ci.yml

@@ -0,0 +1,22 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+
+jobs:
+  Tests:
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 6
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+      fail-fast: false
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-node@v1
+    - run: npm ci
+    - run: npm run build
+    - run: npm test