Merge pull request #19 from recurly/readme-pagination

Quick fix NextPage() to Fetch()

README.md

@@ -109,7 +109,7 @@ After fetching the last page, `HasMore` will be false.
 
 ```go
 for accounts.HasMore {
-    err := accounts.NextPage()
+    err := accounts.Fetch()
     if err {
         fmt.Printf("Failed to retrieve next page: %v", err)
         break