Bump actions/setup-node from v1 to v2.1.5

Bumps [actions/setup-node](https://github.com/actions/setup-node) from v1 to v2.1.5.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v1...46071b5)

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

.github/workflows/prettier.yml

@@ -10,7 +10,7 @@ jobs:
         with:
           path: ~/.npm
           key: npm-${{ hashFiles('**/package-lock.json') }}
-      - uses: actions/setup-node@v1
+      - uses: actions/setup-node@v2.1.5
         with:
           node-version: 12
       - run: npm install