update github action

Author: kazupon

.github/workflows/test.yml

@@ -3,18 +3,26 @@ on:
   push:
     branches-ignore:
       - gh-pages
+      - releases/**
   pull_request:
+    branches-ignore:
+      - gh-pages
+      - releases/**
+    types:
+      - opened
+      - synchronize
+      - reopened
 env:
   CI: true
 
 jobs:
   test:
-    name: "Test on Node.js ${{ matrix.node }} OS: ${{matrix.os}}"
+    name: 'Test on Node.js ${{ matrix.node }} OS: ${{matrix.os}}'
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        node: [12, 14]
+        node: [12, 14, 16]
     steps:
       - name: Checkout
         uses: actions/checkout@v2