WIP: Resolve "Add the packaging metadata to build the duniter snap"

Closes #1290

The original PR comes from a branch of a github fork, it would ask elopio to recreate its branch on gitlab !

Message d'origine de elopio :

Hello!

I recently found your project, and took the chance last week to give it a try while testing a new snapcraft release. If you haven't heard about snaps before, here's a lot of info: https://snapcraft.io/

I think it would be great if you push it to the store. This package only has the server, but if you like the idea, the tools, and exposing duniter to all the Ubuntu users, we can talk about making snaps for cesium and the other components.

To test this in an Ubuntu 16.04 machine:

$ sudo apt install git snapcraft
$ git clone https://github.com/elopio/duniter
$ cd duniter
$ git checkout snapcraft
$ snapcraft
$ sudo snap install *.snap --dangerous
$ duniter config --port 8000 --ipv4 127.0.0.1
$ duniter start
$ sensible-browser localhost:8000

If you have any questions, please let me kno.

pura vida.

closed