ci: enable parallel coveralls reports (#164)

Author: scriptcoded

.github/workflows/test.yml

@@ -10,6 +10,8 @@ jobs:
 
     strategy:
       matrix:
+        # If you change these, don't forget to update carryforward in the finish
+        # step as well.
         node-version: [14, 16, 18]
 
     steps:
@@ -28,3 +30,17 @@ jobs:
       uses: coverallsapp/github-action@v2
       with:
         github-token: ${{ secrets.GITHUB_TOKEN }}
+        parallel: true
+        flag-name: ${{ matrix.node-version }}
+
+  finish:
+    needs: test
+    if: ${{ always() }}
+    runs-on: ubuntu-latest
+    steps:
+    - name: Coveralls Finished
+      uses: coverallsapp/github-action@v2
+      with:
+        github-token: ${{ secrets.GITHUB_TOKEN }}
+        parallel-finished: true
+        carryforward: "14,16,18"