Update actions/checkout to v2

Author: othercorey

.github/workflows/ci.yml

@@ -21,9 +21,7 @@ jobs:
             prefer-lowest: 'prefer-lowest'
 
     steps:
-    - uses: actions/checkout@v1
-      with:
-        fetch-depth: 1
+    - uses: actions/checkout@v2
 
     - name: Setup PHP
       uses: shivammathur/setup-php@v2
@@ -48,9 +46,7 @@ jobs:
 
     - name: Composer install
       run: |
-        if [[ ${{ matrix.php-version }} == '8.0' ]]; then
-          composer install --ignore-platform-reqs
-        elif ${{ matrix.prefer-lowest == 'prefer-lowest' }}; then
+        if ${{ matrix.prefer-lowest == 'prefer-lowest' }}; then
           composer update --prefer-lowest --prefer-stable
         else
           composer install
@@ -69,9 +65,7 @@ jobs:
     runs-on: ubuntu-18.04
 
     steps:
-    - uses: actions/checkout@v1
-      with:
-        fetch-depth: 1
+    - uses: actions/checkout@v2
 
     - name: Setup PHP
       uses: shivammathur/setup-php@v2
@@ -85,7 +79,7 @@ jobs:
       run: composer install
 
     - name: Run phpcs
-      run: vendor/bin/phpcs -p src/ tests/
+      run: vendor/bin/phpcs --report=checkstyle -p src/ tests/ | cs2pr
 
     - name: Run psalm
       run: psalm --output-format=github