Fix flake8 warning in schema.py
Fix flake8 warning in schema.py

rsalmaso/apistar,rsalmaso/apistar,encode/apistar,tomchristie/apistar,tomchristie/apistar,tomchristie/apistar,encode/apistar,tomchristie/apistar,rsalmaso/apistar,encode/apistar,rsalmaso/apistar,encode/apistar