Bump actions/cache from 2.1.6 to 2.1.7

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] <[email protected]>

.github/workflows/maven.yml

@@ -35,7 +35,7 @@ jobs:
         uses: actions/[email protected]
 
       - name: Set up cache for ~./m2/repository
-        uses: actions/[email protected].6
+        uses: actions/[email protected].7
         with:
           path: ~/.m2/repository
           key: maven-${{ matrix.os }}-java${{ matrix.java }}-${{ hashFiles('**/pom.xml') }}