Allow Symfony 4 and avoid deprecation warning with Symfony 3.4

Author: VolCh

composer.json

@@ -13,7 +13,7 @@
   "minimum-stability": "beta",
   "require": {
     "php": "^5.6 || ~7.0",
-    "symfony/process": "^2.8 || ^3.1",
+    "symfony/process": "^2.8 || ^3.1 || ^4.0",
     "ext-curl": "*",
     "ext-zip": "*"
   },
@@ -25,7 +25,7 @@
     "php-mock/php-mock-phpunit": "^1.1",
     "php-coveralls/php-coveralls": "^1.0.2",
     "guzzle/guzzle": "^3.4.1",
-    "symfony/var-dumper": "^3.3"
+    "symfony/var-dumper": "^3.3 || ^4.0"
   },
   "autoload": {
     "psr-4": {

lib/Remote/Service/DriverService.php

@@ -145,11 +145,20 @@ protected static function checkExecutable($executable)
      */
     private function createProcess()
     {
-        $processBuilder = (new ProcessBuilder())
-            ->setPrefix($this->executable)
-            ->setArguments($this->args)
-            ->addEnvironmentVariables($this->environment);
+        // BC: ProcessBuilder deprecated since Symfony 3.4 and removed in Symfony 4.0.
+        if (class_exists(ProcessBuilder::class)
+            && false === mb_strpos('@deprecated', (new \ReflectionClass(ProcessBuilder::class))->getDocComment())
+        ) {
+            $processBuilder = (new ProcessBuilder())
+                ->setPrefix($this->executable)
+                ->setArguments($this->args)
+                ->addEnvironmentVariables($this->environment);
+
+            return $processBuilder->getProcess();
+        }
+        // Safe to use since Symfony 3.3
+        $commandLine = array_merge([$this->executable], $this->args);
 
-        return $processBuilder->getProcess();
+        return new Process($commandLine, null, $this->environment);
     }
 }