Apply updates from cookiecutter

This automated commit applies the latest updates from our cookiecutters [1] to
this repo.

[1]: https://github.com/hypothesis/cookiecutters

tox.ini

@@ -37,7 +37,7 @@ deps =
     lint: pycodestyle
     lint,tests: pytest-mock
     lint,tests,functests: pytest
-    tests: pytest-coverage
+    tests: pytest-cov
     coverage: coverage[toml]
     lint,tests,functests: factory-boy
     lint,tests,functests: pytest-factoryboy