Move before create trigger to top

[yogibear54]

Discovering why I was coming up with problems that appeared like the validations were occuring before the before_create was called.

I then noticed update had before_update at the beginning of the method, so thought it would be useful for insert to be like this as well.

[jamierumbelow]

Thanks! Could you write a quick regression test to check it, please? I'll merge it in :)