able to cover more testing scenarios
Currently, its hard to implement test suite for payments because
mockpayments is on to high level and we cannot emulate many things e.g.
adding credit card. This change is first to be able to add mock for
Stripe client and do more granular tests.
Change-Id: Ied85d4bd0642debdffe1161657c1e475202e9d23
To avoid including multiple months in a single invoice, we need all
inspector's invoice commands to run in for specific period.
See https://storjlabs.atlassian.net/browse/USR-725
Change-Id: I3637dc189234f02350daca8d897c21765762ea55
