add "latest" to nodejs (it's nodejs v17 right now)

Author: gfx

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        node-version: ['12', '14', '16']
+        node-version: ['12', '14', '16', latest]
 
     steps:
     - uses: actions/checkout@v2