Update prod account creation link

README.md

@@ -40,7 +40,7 @@ Report bugs or suggest features using [issue tracker at GitHub](https://github.c
 
 Account creation
 -------------------------------------------------
-You can get yourself a [free sandbox account](https://www.mangopay.com/signup/create-sandbox/) or sign up for a [production account](https://www.mangopay.com/signup/submit-your-app/go-live/) (note that validation of your production account can take a few days, so think about doing it in advance of when you actually want to go live).
+You can get yourself a [free sandbox account](https://www.mangopay.com/signup/create-sandbox/) or sign up for a [production account](https://www.mangopay.com/signup/production-account/) (note that validation of your production account can take a few days, so think about doing it in advance of when you actually want to go live).
 
 Inspiration
 -----------
@@ -50,4 +50,4 @@ The data model of python-mangopay is highly inspired by [peewee](https://github.
 Credits
 -----------
 
-The inital basis of this SDK was generously coded and donated by [Ulule](https://www.ulule.com/)
+The inital basis of this SDK was generously coded and donated by [Ulule](https://www.ulule.com/)