Add attribution info to metadata, if available

[johanhelsing]

No description provided.

[johanhelsing]

I needed this for my use case. Take or leave it :)

[johanhelsing]

Example:

~/dev/oga oga describe --verbose 12-medieval-signs
{
    "attribution": "J. W. Bjerk (eleazzaar) -- www.jwbjerk.com/art",
    "author": "eleazzaar",
    "favorites": 33,
    "files": [
        {
            "etag": "7fd3cc-4c181f2113ac0",
            "id": "12-medieval-signs_0.zip",
            "size": 8377292
        }
    ],
    "id": "12-medieval-signs",
    "licenses": [
        "CC-BY 3.0",
        "CC-BY-SA 3.0",
        "GPL 3.0",
        "GPL 2.0"
    ],
    "tags": [
        "sign",
        "RPG",
        "Fantasy",
        "medieval",
        "Fish",
        "blacksmith",
        "magic",
        "weapon",
        "Inn",
        "shop",
        "unicorn"
    ],
    "type": "Texture"
}

[numberoverzero]

I have a slight preference for the parser including every field, even if it's None. It's a signal that the parser looked but didn't find it, whereas a new field would be omitted entirely by an older parser.

Suggested change

	"files": files}
	if attribution != None:
	ret["attribution"] = attribution
	return ret
	"files": files,
	"attribution": attribution}
	return ret

[numberoverzero]

same comment as above, I'd prefer "attribution" be included even when None. stripping empty values at the CLI could be an option but the model shouldn't omit them.

[johanhelsing]

I don't mind either way is fine by me.

[numberoverzero]

Looks great, thanks for the pull request! I'm happy to add this functionality.

If you'd prefer I can merge this as-is and make those changes, just let me know.

[johanhelsing]

Just merge and make the edits you want to :)

[numberoverzero]

Thanks again for the contribution!