Add compatibility with symfony 5 process (#35)

* add compatibility with symfony 5 process

* add check method exists

Author: RuSPanzer

src/Extension/PhiremockProcess.php

@@ -93,7 +93,11 @@ private function initProcess($ip, $port, $debug, $expectationsPath, $phiremockPa
         $commandline[] = $logFile;
         $commandline[] = '2>&1';
 
-        $this->process = new Process(implode(' ', $commandline));
+        if (method_exists(Process::class, 'fromShellCommandline')) {
+            $this->process = Process::fromShellCommandline(implode(' ', $commandline));
+        } else {
+            $this->process = new Process(implode(' ', $commandline));
+        }
     }
 
     /**