add setup.py and bump to 0.3.0

Signed-off-by: Paul Spooren <[email protected]>

setup: v0.2.4

readme: add docker badge

config: use /etc/asu/config.yml if exists

fixup: LIME_RELEASE for upgrades

Testing and master are two different branches and LibreMesh renames it's
VERSION based on this branch. Therefore both testing/unstable would
always request a "master" version from the server. Now it's separated.