Merge pull request #175 from PrivateStorageio/174.calculate-price

docs/source/interface.rst

setup.cfg

src/_zkapauthorizer/controller.py

src/_zkapauthorizer/pricecalculator.py

src/_zkapauthorizer/resource.py

src/_zkapauthorizer/storage_common.py

src/_zkapauthorizer/tests/strategies.py

src/_zkapauthorizer/tests/test_client_resource.py

src/_zkapauthorizer/tests/test_pricecalculator.py

src/_zkapauthorizer/tests/test_strategies.py