erp5_wechat_secure_payment: add base BT for Wechat payment

/reviewed-on !988
4 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Master

02:28:44

failed ERP5.UnitTest-Master

03:43:53

passed SlapOS.Eggs.UnitTest-Master.Python2

00:20:18

passed SlapOS.Eggs.UnitTest-Master.Python3

00:15:10