cloudbilling-cli doc concepts: https://cloud.google.com/billing/docs/concepts?hl=en API doc: https://cloud.google.com/billing/reference/rest/v1/billingAccounts?hl=en google-api-client (ruby): https://github.com/googleapis/google-api-ruby-client/blob/master/generated/google/apis/cloudbilling_v1/service.rb