Update test.yml v12x, v14x to v18x, v20x (#15)

Update `test.yml` v12x, v14x to v18x, v20x

Author: EmptyWork

.github/workflows/test.yml

@@ -15,7 +15,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [12.x, 14.x, 16.x]
+        node-version: [16.x, 18.x, 20.x]
 
     steps:
     - uses: actions/checkout@v2