Allow custom sheet name in the XLSX writer

Added setter
Added test
Updated README

src/Spout/Writer/Internal/XLSX/Worksheet.php

@@ -97,7 +97,7 @@ EOD;
     public function getId()
     {
         // sheet number is zero-based, while ID is 1-based
-        return $this->externalSheet->getSheetNumber() + 1;
+        return $this->externalSheet->getNumber() + 1;
     }
 
     /**

src/Spout/Writer/Sheet.php

@@ -30,7 +30,7 @@ class Sheet
     /**
      * @return int Number of the sheet, based on order of creation (zero-based)
      */
-    public function getSheetNumber()
+    public function getNumber()
     {
         return $this->sheetNumber;
     }
@@ -42,4 +42,14 @@ class Sheet
     {
         return $this->name;
     }
+
+    /**
+     * @param string $name Name of the sheet
+     * @return \Box\Spout\Writer\Sheet
+     */
+    public function setName($name)
+    {
+        $this->name = $name;
+        return $this;
+    }
 }