Update spa.yml

Add matrix for node 10.x

Author: wviriya

.github/workflows/spa.yml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       matrix:
         # https://docs.microsoft.com/en-us/azure/azure-functions/functions-versions?tabs=csharp%2Cv4#languages
-        node-version: [14.x, 12.x]
+        node-version: [14.x, 12.x, 10.x]
 
     steps:
     - uses: actions/checkout@v2