Update node.js.yml

Author: nicolas-van

.github/workflows/node.js.yml

@@ -8,11 +8,14 @@ on: ["push", "pull_request"]
 jobs:
   test:
 
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
 
     strategy:
       matrix:
         node-version: [12.x, 13.x, 14.x, 15.x, 16.x]
+        
+    container:
+      image: ubuntu:18.04
 
     steps:
     - uses: actions/checkout@v2