Bump actions/cache from 2.1.5 to 2.1.6

Bumps [actions/cache](https://github.com/actions/cache) from 2.1.5 to 2.1.6.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](https://github.com/actions/cache/compare/v2.1.5...v2.1.6)

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

.github/workflows/maven.yml

@@ -32,7 +32,7 @@ jobs:
         
     steps:
     - uses: actions/checkout@v2.3.4
-    - uses: actions/cache@v2.1.5
+    - uses: actions/cache@v2.1.6
       with:
         path: ~/.m2/repository
         key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}

src/changes/changes.xml

@@ -250,7 +250,7 @@
       Migrate assert to Assertions #209.
     </action>
     <action type="update" dev="kinow" due-to="Dependabot">
-      Bump actions/cache from v2 to v2.1.5 #214 #225.
+      Bump actions/cache from v2 to v2.1.6 #214 #225 #239.
     </action>
     <action issue="COLLECTIONS-781" type="update" dev="ggregory" due-to="Arturo Bernal, Gary Gregory">
       Add and use CollectionUtils.INDEX_NOT_FOUND constant.