Bump actions/cache from v2.1.4 to v2.1.5 (#54)

Bumps [actions/cache](https://github.com/actions/cache) from v2.1.4 to v2.1.5.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](https://github.com/actions/cache/compare/v2.1.4...1a9e2138d905efd099035b49d8b7a3888c653ca8)

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

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

.github/workflows/build.yaml

@@ -94,7 +94,7 @@ jobs:
           env
 
       - name: Go module cache
-        uses: actions/cache@v2.1.4
+        uses: actions/cache@v2.1.5
         with:
           path: ~/go/pkg/mod
           key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}