Yun 17.11 Reboot prerelease

Hello, thanks to new update.

I tried it but got a fail. So, I set up it manually resulting in a success.

Anyone who try it manually should be careful at some points.

You should use a new disk-expander util because old one yields a insufficient memory alarm.
(use the new version in the go-update package).

Next, you should update your u-boot at first due to a large package.

I am really happy due to this new update. I have some problems in using the python in the old version
(especially pip was not working due to certification problem). Now, it works fine.
Thanks.