Allow users to set their AWS account within exported functions?

[sckott]

from #10

Possibly via some helper fxn, ideally not through every function, which would add extra work for everyone.

e.g., costexplorer has

costexplorer(
  config = list(),
  credentials = list(),
  endpoint = NULL,
  region = NULL
)

We initialize that list of functions for cost explorer ourselves - we could have helper funs to allow users to set creds so whenever it initializes they are used

Originally posted by @sckott in #10 (comment)