Remove unsupported PHP versions from workflow

7.1 and 7.2 are no longer supported by PHP nor should be by our SDK

Author: patrikjuvonen

.github/workflows/php.yml

@@ -2,26 +2,23 @@ name: PHP Composer
 
 on:
   push:
-    branches: [ master ]
+    branches: master
   pull_request:
-    branches: [ master ]
+    branches: master
 
 jobs:
   build:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php-versions: ['7.1', '7.2', '7.3', '7.4']
+        php-versions: ['7.3', '7.4']
     name: Build PHP version ${{ matrix.php-versions }}
     steps:
     - uses: actions/checkout@v2
-
     - uses: shivammathur/setup-php@v2
       with:
         php-version: ${{ matrix.php-versions }}
-
     - name: Install dependencies
       run: composer install --prefer-dist --no-progress
-
     - name: Run test suite
       run: composer test