build: Bump actions/cache from 2.1.6 to 2.1.7 (#23)

Bumps [actions/cache](https://github.com/actions/cache) from 2.1.6 to 2.1.7.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](actions/cache@v2.1.6...v2.1.7)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
       - uses: "actions/checkout@v2.4.0"
 
       - name: "Cache Docker layers"
-        uses: "actions/cache@v2.1.6"
+        uses: "actions/cache@v2.1.7"
         with:
           path: "/tmp/.buildx-cache"
           key: "${{ runner.os }}-buildx-${{ github.sha }}"
@@ -64,7 +64,7 @@ jobs:
       - uses: "actions/checkout@v2.4.0"
 
       - name: "Cache Docker layers"
-        uses: "actions/cache@v2.1.6"
+        uses: "actions/cache@v2.1.7"
         with:
           path: "/tmp/.buildx-cache"
           key: "${{ runner.os }}-buildx-${{ github.sha }}"