Use node 14 when publishing the package node to npm

Author: keichi

.github/workflows/npmpublish.yml

@@ -14,7 +14,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
       - run: npm ci
       - run: npm test
 
@@ -25,7 +25,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
           registry-url: https://registry.npmjs.org/
       - run: npm ci
       - run: npm publish