Bump actions/setup-node from 1 to 2.1.5

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 1 to 2.1.5.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v1...v2.1.5)

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

Author: dependabot[bot]

.github/workflows/tests.yml

@@ -27,7 +27,7 @@ jobs:
           fetch-depth: '2'
 
       - name: Test on Node ${{ matrix.node-version }}
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v2.1.5
         with:
           node-version: ${{ matrix.node-version }}