Use Slevomat CS

.travis.yml

@@ -1,9 +1,6 @@
 language: php
 
 php:
-    - 5.6 # security support until 31/12/2018
-    - 7.0 # security support until 03/12/2018
-    - 7.1 # security support until 01/12/2019
     - 7.2 # security support until 30/11/2020
     - 7.3 # security support until 06/12/2021
     - 7.4 # security support until 28/11/2022

Symfony/Sniffs/Arrays/MultiLineArrayCommaSniff.php

@@ -96,9 +96,11 @@ public function process(File $phpcsFile, $stackPtr)
                 while ($lastCommaPtr < $closePtr -1) {
                     $lastCommaPtr++;
 
-                    if ($tokens[$lastCommaPtr]['code'] !== T_WHITESPACE
-                        && $tokens[$lastCommaPtr]['code'] !== T_PHPCS_IGNORE
-                        && $tokens[$lastCommaPtr]['code'] !== T_COMMENT
+                    if (!in_array(
+                        $tokens[$lastCommaPtr]['code'],
+                        [T_WHITESPACE, T_PHPCS_IGNORE, T_COMMENT],
+                        true
+                    )
                     ) {
                         $fix = $phpcsFile->addFixableError(
                             'Add a comma after each item in a multi-line array',

Symfony/Sniffs/Classes/PropertyDeclarationSniff.php

@@ -68,10 +68,7 @@ public function process(File $phpcsFile, $stackPtr)
     {
         $tokens = $phpcsFile->getTokens();
 
-        $end = null;
-        if (isset($tokens[$stackPtr]['scope_closer'])) {
-            $end = $tokens[$stackPtr]['scope_closer'];
-        }
+        $end = $tokens[$stackPtr]['scope_closer'] ?? null;
 
         $scope = $phpcsFile->findNext(
             T_FUNCTION,

Symfony/Sniffs/Commenting/AnnotationsSniff.php

@@ -28,7 +28,7 @@
  */
 class AnnotationsSniff implements Sniff
 {
-    const PATTERN = '/^@([^\\\(]+).*$/i';
+    private const PATTERN = '/^@([^\\\(]+).*$/i';
 
     /**
      * Registers the tokens that this sniff wants to listen for.