Founded returns nil if any fields are nil

[fletchrichman]

The founded method will return nil if any of the fields are nil, and the individual fields are not accessible, so when a company gives founded_year and founded_month but not founded_day, there is no way to access any of the information.

I think just adding founded_year, founded_month, and founded_day to the attr_reader would fix this, happy to do a pull request if you would like.

[tylercunnion]

Yeah, putting attr_readers in for those is probably the way to go. I left them out initially as I was working under the assumption that the dates were an all or nothing proposition (since of course there's no actual doc or specification). I'll go ahead and add this in, and I think this also means the founded, deadpooled, etc. methods should be deprecated if they can't be relied upon.