updated docblock of jsonSerialize()

Author: 1franck

Cmfcmf/OpenWeatherMap/Util/Unit.php

@@ -149,9 +149,10 @@ public function getFormatted()
 
     /**
      * Get Unit properties when encoding to JSON
+     *
      * @return array
      */
-    public function jsonSerialize ()
+    public function jsonSerialize()
     {
         return [
             'value' => $this->getValue(),