ci(nvmrc): simplified building based on the nvmrc file by leveraging the new setup-node support

Author: travi

.github/workflows/node-ci.yml

@@ -18,13 +18,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - name: Read .nvmrc
-        run: echo ::set-output name=NVMRC::$(cat .nvmrc)
-        id: nvm
       - name: Setup node
         uses: actions/setup-node@v2
         with:
-          node-version: ${{ steps.nvm.outputs.NVMRC }}
+          node-version-file: '.nvmrc'
       - uses: bahmutov/npm-install@v1
       - run: npm test
       - name: Upload coverage data to Codecov