Merge pull request #77 from benja-M-1/master

Fix the exception "Invalid argument supplied for foreach()"

src/Composer/DependencyResolver/Request.php

@@ -25,6 +25,7 @@ class Request
     public function __construct(Pool $pool)
     {
         $this->pool = $pool;
+        $this->jobs = array();
     }
 
     public function install($packageName, LinkConstraintInterface $constraint = null)