Build(deps): Bump actions/cache from v1 to v2

Bumps [actions/cache](https://github.com/actions/cache) from v1 to v2.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](actions/cache@v1...b820478)

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

.github/workflows/integrate.yml

@@ -42,7 +42,7 @@ jobs:
         run: "echo \"::set-output name=directory::$(composer config cache-dir)\""
 
       - name: "Cache dependencies installed with composer"
-        uses: "actions/cache@v1"
+        uses: "actions/cache@v2"
         with:
           path: "${{ steps.determine-composer-cache-directory.outputs.directory }}"
           key: "php-${{ matrix.php-version }}-composer-${{ matrix.dependencies }}-${{ hashFiles('**/composer.lock') }}"
@@ -97,7 +97,7 @@ jobs:
         run: "echo \"::set-output name=directory::$(composer config cache-dir)\""
 
       - name: "Cache dependencies installed with composer"
-        uses: "actions/cache@v1"
+        uses: "actions/cache@v2"
         with:
           path: "${{ steps.determine-composer-cache-directory.outputs.directory }}"
           key: "php-${{ matrix.php-version }}-composer-${{ matrix.dependencies }}-phpunit-${{ matrix.phpunit-version }}-${{ hashFiles('**/composer.lock') }}"
@@ -162,7 +162,7 @@ jobs:
         run: "echo \"::set-output name=directory::$(composer config cache-dir)\""
 
       - name: "Cache dependencies installed with composer"
-        uses: "actions/cache@v1"
+        uses: "actions/cache@v2"
         with:
           path: "${{ steps.determine-composer-cache-directory.outputs.directory }}"
           key: "php-${{ matrix.php-version }}-composer-${{ matrix.dependencies }}-${{ hashFiles('**/composer.lock') }}"