Add content_owner.claims to list Content ID claims

Add content_owner.claims to list Content ID claims

A new Claim class is introduced to list YouTube ContentID Claims.
See https://developers.google.com/youtube/partner/docs/v1/claims

content_owner.claims also accepts `where` to only list claims that
match a set of IDs, such as:

    content_owner.claims.where id: 'A1234,B1345'
    content_owner.claims.where asset_id: 'A123'
    content_owner.claims.where video_id: 'x1234'
    content_owner.claims.where q: 'something in the title'

I don't really see a need to be explicit about the parameters, if the user wants to send a new parameter to the API, let them.  (examples: new parameters are introduced, a trace token is given to us, etc etc).

By slicing these four parameters out aren't you also preventing any of the optional parameters from being sent?

![image](https://cloud.githubusercontent.com/assets/2391584/3675784/a032068a-1281-11e4-9830-d04a83405a06.png)