Add support for AIX

Add support for AIX. Currently disto returns the following for a AIX 7.2:

{
    "codename": "",
    "id": "aix",
    "like": "",
    "version": "2",
    "version_parts": {
        "build_number": "",
        "major": "2",
        "minor": ""
    }
}

Source could be cmd oslevel:

$ oslevel
7.2.0.0

7 --> major 2 --> minor

[nir0s]

@HorlogeSkynet, sounds good. However, while I don’t know AIX, it doesn’t make sense to me that there isn’t a file with that info. Does AIX have a magical way of storing this info that we can’t read?

[nir0s]

Hehe, I’m the one missing something. I didn’t read the previous comments.