adding flatpak manifest + python dependencies for flatpak

[jeteokeeffe]

I've added the flatpak manifest along with python dependencies file (necessary to create flatpak application). If you have any problems, questions or whatever, let me know.

You'll need to follow these steps to get the app to flathub repository.
https://github.com/flathub/flathub/wiki/App-Submission#how-to-submit-an-app

[genodeftest]

Do we have to have fixed versions in the python-depends.json file? I.e. every time any of these packages is updated, we need to change this file?

[jeteokeeffe]

Yes, the python dependencies are locked to a specific version. I have a python dependencies file that flatpak needs to build that locks versions.

For example

"modules": [
        {
            "name": "python3-dbus-python",
            "buildsystem": "simple",
            "build-commands": [
                "pip3 install --no-index --find-links=\"file://${PWD}\" --prefix=${FLATPAK_DEST} dbus-python"
            ],
            "sources": [
                {
                    "type": "file",
                    "url": "https://files.pythonhosted.org/packages/62/7e/d4fb56a1695fa65da0c8d3071855fa5408447b913c58c01933c2f81a269a/dbus-python-1.2.16.tar.gz",
                    "sha256": "11238f1d86c995d8aed2e22f04a1e3779f0d70e587caffeab4857f3c662ed5a4"
                }
            ]
        },