Update GH action

.github/workflows/test.yml

 name: Test
-on: [push]
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
 
 jobs:
-  build:
+  test:
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        node-version: [14.x]
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-node@v1
+      - uses: actions/setup-node@v2
         with:
-          node-version: ${{ matrix.node-version }}
+          node-version: '14'
       - run: npm ci
       - run: npm test