Use black to format code

• Add black requirement and force toml package to be installed with version 0.10.1 to avoid this error:

ERROR: black 21.5b1 has requirement toml>=0.10.1, but you'll have toml 0.10.0 which is incompatible.

• Upload black arrangements in repo

reformatted pymasmovil/errors/http_error.py
reformatted pymasmovil/errors/mm_error.py
reformatted pymasmovil/errors/exceptions.py
reformatted pymasmovil/client.py
reformatted pymasmovil/models/account.py
reformatted pymasmovil/models/asset.py
reformatted pymasmovil/models/contract.py
reformatted pymasmovil/models/new_line_request.py
reformatted tests/fake_response.py
reformatted pymasmovil/models/session.py
reformatted pymasmovil/models/order_item.py
reformatted setup.py
reformatted tests/test_http_error.py
reformatted tests/test_mm_error.py
reformatted tests/test_client.py
reformatted tests/test_new_line_request.py
reformatted tests/test_account.py
reformatted tests/test_asset.py
reformatted tests/test_order_item.py
reformatted tests/test_session.py
All done! ✨ 🍰 ✨
20 files reformatted, 4 files left unchanged.