Bump actions/setup-node from v1 to v2.1.2

Bumps [actions/setup-node](https://github.com/actions/setup-node) from v1 to v2.1.2.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/v1...c6fd00ceb9747fb23ffdf72987450a2664414867)

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

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
           tag-schedule: weekly
 
       - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v2.1.2
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm ci