test: run tests against node 18 (#637)

Author: yharaskrik

.github/workflows/nodejs.yml

@@ -14,7 +14,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [10.x, 12.x, 14.x, 16.x]
+        node-version: [10.x, 12.x, 14.x, 16.x, 18.x]
 
     steps:
     - uses: actions/[email protected]