Fix build errors

.github/workflows/ci.yml

@@ -0,0 +1,26 @@
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+jobs:
+  ci:
+    name: 'build and test'
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node: [ '10', '12' ]
+      fail-fast: true
+    steps:
+    - uses: actions/checkout@v1
+    - uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node }}
+    - name: install
+      run: npm ci && lerna bootstrap
+    - name: lint
+      run: npm run lint
+    - name: test
+      run: npm test