[bug 1196244] Remove '--fake' option from chief migration command.
[bug 1196244] Remove '--fake' option from chief migration command.

* More pythonic syntax

akatsoulas/mozillians,brian-yang/mozillians,johngian/mozillians,anistark/mozillians,fxa90id/mozillians,anistark/mozillians,brian-yang/mozillians,brian-yang/mozillians,safwanrahman/mozillians,mozilla/mozillians,fxa90id/mozillians,safwanrahman/mozillians,anistark/mozillians,mozilla/mozillians,akatsoulas/mozillians,johngian/mozillians,chirilo/mozillians,johngian/mozillians,fxa90id/mozillians,brian-yang/mozillians,safwanrahman/mozillians,chirilo/mozillians,chirilo/mozillians,akatsoulas/mozillians,fxa90id/mozillians,akatsoulas/mozillians,mozilla/mozillians,johngian/mozillians,chirilo/mozillians,anistark/mozillians,mozilla/mozillians,safwanrahman/mozillians