Bump actions/cache from v2.1.4 to v2.1.5 (#26)

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
         with:
           node-version: 15.12.0
 
-      - uses: actions/cache@v2.1.4
+      - uses: actions/cache@v2.1.5
         with:
           path: node_modules
           key: npm-${{ hashFiles('package-lock.json') }}