Add costs to client

[emachnic]

This exposes costs from the API for an account. Given an account, you should be able to get the array of costs for that account.

Example:

costs = account.costs.all

If you have the costs array, you should then be able to select any costs that fit your needs:

costs.select { |c| c.level == 'final' }

[jacobo]

LGTM, although note: you could just request the costs where level: 'total' instead of requesting all and then selecting the 'total' ones

[lanej]

params["id"]