LilyDev 0.3 released

[Federico Bruni]

https://github.com/fedelibre/LilyDevOS/releases/tag/v0.3


New in this release:

   Docker container based on Ubuntu 18.04: download this repository 
and follow the instructions in docker/.

   The images uploaded in Releases are based on Debian 9 Stretch. 
(Fedora images, upgraded to version 29, can still be generated using 
the Makefile)

   The Debian virtual machine (lilydev-debian-vm) is using the XFCE 
desktop environment.

   Debian images have all the dependencies to run GUB.