Bump actions/cache from v1 to v2.1.4

Bumps [actions/cache](https://github.com/actions/cache) from v1 to v2.1.4.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](actions/cache@v1...26968a0)

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

Author: dependabot[bot]

.github/workflows/continuous-integration.yml

@@ -33,14 +33,14 @@ jobs:
         run: echo "::set-output name=dir::$(composer config cache-files-dir)"
 
       - name: Cache composer dependencies
-        uses: actions/cache@v1
+        uses: actions/cache@v2.1.4
         with:
           path: ${{ steps.composer-cache.outputs.dir }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.json') }}
           restore-keys: ${{ runner.os }}-composer-
 
       - name: Cache PHPUnit cache
-        uses: actions/cache@v1
+        uses: actions/cache@v2.1.4
         with:
           path: tests/.phpunit.result.cache
           key: ${{ runner.os }}-phpunit-${{ github.sha }}

.github/workflows/publish.yml

@@ -39,7 +39,7 @@ jobs:
         run: echo "::set-output name=dir::$(composer config cache-files-dir)"
 
       - name: Cache composer dependencies
-        uses: actions/cache@v1
+        uses: actions/cache@v2.1.4
         with:
           path: ${{ steps.composer-cache.outputs.dir }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.json') }}