[chore] Add latest node versions to CI (#207)

Author: benmccann

.github/workflows/ci.yml

@@ -5,7 +5,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        node-version: ["10", "12", "14"]
+        node-version: ["10", "12", "14", "16", "18"]
         os: [ubuntu-latest, windows-latest]
     name: Test on Node v${{ matrix.node-version }} on ${{ matrix.os }}
     steps: