docs(testing): fix small typo (#2401)

Author: maxime1992

public/docs/ts/latest/guide/testing.jade

@@ -142,7 +142,7 @@ a#setup
 
 .alert.is-helpful
   :marked
-    If youur application was based on the QuickStart repository,
+    If your application was based on the QuickStart repository,
     you can skip the rest of this section and get on with your first test.
     The QuickStart repo provides all necessary setup.