create sites directory

cli/Valet/Configuration.php

@@ -25,6 +25,7 @@ function install()
     {
         $this->createConfigurationDirectory();
         $this->createDriversDirectory();
+        $this->createSitesDirectory();
         $this->createExtensionsDirectory();
         $this->writeBaseConfiguration();
 
@@ -60,6 +61,16 @@ function createDriversDirectory()
         );
     }
 
+    /**
+     * Create the Valet sites directory.
+     *
+     * @return void
+     */
+    function createSitesDirectory()
+    {
+        $this->files->ensureDirExists(VALET_HOME_PATH.'/Sites', user());
+    }
+
     /**
      * Create the directory for the Valet extensions.
      *