Add Node 18 CI

Author: thornjad

.github/workflows/node.js.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [12.x, 14.x, 16.x, 17.x]
+        node-version: [12.x, 14.x, 16.x, 17.x, 18.x]
         os: [ubuntu-latest, macOS-latest, windows-latest]
 
     steps: