Fixed setting width of Cell Style

The setWidth method did not change the width in the style, seems to be a small mistake.
Now the width is correctly for the Cell Style.

Author: rikvdlooi

src/PhpWord/Style/Cell.php

@@ -299,7 +299,7 @@ public function getWidth()
      */
     public function setWidth($value)
     {
-        $this->setIntVal($value);
+        $this->width = $this->setIntVal($value);
 
         return $this;
     }