First stab are replacing squizlabs/php_codesniffer with friendsofphp/…

…php-cs-fixer

.php_cs

@@ -0,0 +1,8 @@
+<?php declare(strict_types=1);
+
+use ApiClients\Tools\TestUtilities\PhpCsFixerConfig;
+
+return PhpCsFixerConfig::create()->setFinder(
+    PhpCsFixer\Finder::create()
+    ->in(__DIR__)
+);

Makefile

@@ -19,6 +19,9 @@ init:
 cs:
 	composer cs
 
+cs-fix:
+	composer cs-fix
+
 unit:
 	composer run-script unit --timeout=0
 

composer.json

@@ -10,11 +10,11 @@
   "require": {
     "php": "^7.0",
     "clue/block-react": "^1.1",
+    "friendsofphp/php-cs-fixer": "^2.3",
     "jakub-onderka/php-console-highlighter": "^0.3.2",
     "jakub-onderka/php-parallel-lint": "^0.9.2",
     "phake/phake": "^2.3",
-    "phpunit/phpunit": "^6.0",
-    "squizlabs/php_codesniffer": "^2.6"
+    "phpunit/phpunit": "^6.0"
   },
   "autoload": {
     "psr-4": {
@@ -35,7 +35,11 @@
     "ensure-installed": "composer install --ansi -n -q",
     "cs": [
       "@ensure-installed",
-      "phpcs --standard=PSR2 src/"
+      "php-cs-fixer fix --config=.php_cs --path-mode=intersection --dry-run --verbose --allow-risky=yes --show-progress=estimating"
+    ],
+    "cs-fix": [
+      "@ensure-installed",
+      "php-cs-fixer fix --config=.php_cs --verbose --diff --allow-risky=yes --show-progress=estimating"
     ],
     "unit": [
       "@ensure-installed",