Bump actions/cache from v2 to v2.1.4

Bumps [actions/cache](https://github.com/actions/cache) from v2 to v2.1.4.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](https://github.com/actions/cache/compare/v2...26968a09c0ea4f3e233fdddbafd1166051a095f6)

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

.github/workflows/go.yml

@@ -15,7 +15,7 @@ jobs:
         uses: actions/checkout@v2.3.2
 
       - name: Cache go module
-        uses: actions/cache@v2
+        uses: actions/cache@v2.1.4
         with:
           path: ~/go/pkg/mod
           key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}