DHC-1174 - As a developer I can install akanda with devstack from trunk

DHC-1174

This is the first step to make Neutron able to install Akanda
using the Neutron third party interface. The install_akanda
method will take care to install all the library akanda need
including akanda itself

Signed-off-by: Rosario Di Somma <rosario.disomma@dreamhost.com>