Merge pull request #10 from schigh/master

Update README.md @schigh 👌 Thanks for your pr.

README.md

@@ -58,6 +58,8 @@ package main
 
 import (
     "fmt"
+    "os"
+    
     "github.com/Luxurioust/excelize"
 )
 
@@ -86,6 +88,8 @@ package main
 
 import (
     "fmt"
+    "os"
+    
     "github.com/Luxurioust/excelize"
 )