ci: update actions/checkout requirement to v2.3.2 (#27)

Updates the requirements on [actions/checkout](https://github.com/actions/checkout) to permit the latest version.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/commits/2036a08e25fa78bbd946711a407b529a0a1204bf)

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
   test:
     runs-on: ubuntu-18.04
     steps:
-      - uses: actions/[email protected].1
+      - uses: actions/[email protected].2
       - run: docker-compose build
       - run: make build
       - run: make test

.github/workflows/release.yml

@@ -9,7 +9,7 @@ jobs:
   main:
     runs-on: ubuntu-18.04
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.2
 
       - name: Install github/hub
         run: |