Test with one node version

Author: muan

.github/workflows/test.yml

@@ -1,22 +1,16 @@
 name: Node CI
 
-on: [push, pull_request]
+on: [push]
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        node-version: [12.x]
-
     steps:
     - uses: actions/checkout@v1
-    - name: Use Node.js ${{ matrix.node-version }}
+    - name: Use Node.js 12.x
       uses: actions/setup-node@v1
       with:
-        node-version: ${{ matrix.node-version }}
+        node-version: 12.x
     - name: npm install, build, and test
       run: |
         npm ci