Add support for xcdatamodel

[priteshshah1983]

It seems like xcdatamodel is not supported. fullPath is nil:

Project file: key=210833801A3AB97B002BF7B8, name=Yelp v2.xcdatamodel, fullPath=(null)

[priteshshah1983]

Hi @jasperblues,
If you can give me some hints, I'll be happy to create a PR.

Thanks,
Pritesh.

[jasperblues]

Let's have a chat about it on Skype? 'jasperblues'

[priteshshah1983]

I investigated briefly and it seems like XCVersionGroup is not supported:

/* Begin XCVersionGroup section */
        216834A01A3AB8FC00F4325E /* Yelp.xcdatamodeld */ = {
            isa = XCVersionGroup;
            children = (
                210833801A3AB97B002BF7B8 /* Yelp v2.xcdatamodel */,
                216834A11A3AB8FC00F4325E /* Yelp.xcdatamodel */,
            );
            currentVersion = 210833801A3AB97B002BF7B8 /* Yelp v2.xcdatamodel */;
            path = Yelp.xcdatamodeld;
            sourceTree = "<group>";
            versionGroupType = wrapper.xcdatamodel;
        };
/* End XCVersionGroup section */

[priteshshah1983]

My Skype is paf_pshah. I just added you. Let's chat when you have some time.