Bump actions/setup-node from 1 to 2.5.1

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 1 to 2.5.1.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/v1...v2.5.1)

---
updated-dependencies:
- dependency-name: actions/setup-node
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
     - uses: actions/checkout@v2
 
     - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2.5.1
       with:
         node-version: ${{ matrix.node-version }}