Fetch FundingInstrument and Return the appropriate resource

This saves people from metaprogramming module names `::Card` or `::BankAccount` based on hrefs.
We have a new funding instrument going out next week :)

I'm just being idealistic here, it's not a requirement, more like an ideal way to implement this feature. 

@rserna2010 can you take a look and give it the merge if you're OK with it?