Bump actions/checkout from v2.3.3 to v2.3.4 (#155)

Bumps [actions/checkout](https://github.com/actions/checkout) from v2.3.3 to v2.3.4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2.3.3...5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/autoprefixer.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout to latest commit
-        uses: actions/checkout@v2.3.3
+        uses: actions/checkout@v2.3.4
 
       - name: Setup Node
         uses: actions/setup-node@v2.1.2