* feat(testing): Add TestClient class and a pytest example
Add a contextual wrapper for the simulate_* methods and a pytest
example demonstrating its use.
Also deprecate "api" in favor of "app" in TestCase, since these utils
can work with any WSGI app (not just those that express HTTP APIs). This
terminology makes TestCase more consistent with the new simulate_*
functions and with TestClient.
Finally, deprecate "api_class" in TestCase and update the docstring
for the testing module to demonstrate a less hacky alternative for
controlling the api instance type. As a bonus, this avoids having to
try and alias api_class (a class variable).
Partially implements #16
* doc(testing): Clarify 'myapp' example code
fb7ca62fea