Billing improvements

[sckott]

user story: people want to be able to interact with their data via dplyr, etc.

• have two different interfaces in the package? We're only doing costexplorer
  • one for https://www.paws-r-sdk.com/docs/costandusagereportservice/ specifically this fxn - AWS page - I don't have access to this in either prod AWS or test AWS accounts
  • and one for https://www.paws-r-sdk.com/docs/costexplorer/ - this I can work on and have access to
• S3 costs per bucket - for some insane reason there's a complicated workflow for getting per bucket costs, do we deal with that ourselves so users don't have to?
  • not doing now, maybe later
  • see docs for per bucket pricing
  • possibly this paws method could help
• add a vignette with visualizations. maybe incorporate canned plots into the package later.
• function to get rawest data, in list form
• Billing: automatically paginate #39