Test NodeJs 20 (#246)

Author: gpotter2

.github/workflows/unittests.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [8, 10, 12, 14, 15, 16, 18]
+        node-version: [8, 10, 12, 14, 15, 16, 18, 20]
     steps:
       - uses: actions/checkout@v3
       - name: Get Node.js ${{ matrix.node-version }}