add coverage to CI workflow

Author: phn210

.github/workflows/ci.yml

@@ -7,7 +7,8 @@
 name: CI
 on: [push, pull_request]
 jobs:
-  test:
+  build:
+    name: Build
     runs-on: ubuntu-latest
     timeout-minutes: 10
     strategy:
@@ -27,5 +28,13 @@ jobs:
       run: |
         npm run build --if-present
         npm test
+        npm run coverage
       env:
         CI: true
+    - name: Coveralls GitHub Action
+      uses: coverallsapp/github-action@v2.2.3
+      with:
+        github-token: ${{ secrets.COVERALLS_REPO_TOKEN }}
+        flag-name: node-${{ matrix.node-version }}
+        parallel: true
+