Set wrap text style when multiline string encountered

Fixes #10
If a cell contains a multiline string, "wrap text" style option should
automatically be set.

src/Spout/Common/Escaper/XLSX.php

@@ -13,6 +13,9 @@ class XLSX implements EscaperInterface
     /** @var string[] Control characters to be escaped */
     protected $controlCharactersEscapingMap;
 
+    /**
+     *
+     */
     public function __construct()
     {
         $this->controlCharactersEscapingMap = $this->getControlCharactersEscapingMap();