mypy is an experimental optional static type checker for Python that
aims to combine the benefits of dynamic (or "duck") typing and static
typing. While still in development, most features are supported and it's
already being used by real world projects like Sphinx. Let's start small
by integrating it into some of the interfaces that nova exposes. We can
further build upon this if it works out.
This change sets up the boilerplate necessary to use mypy in nova. Type
annotations are not included for any module - these will be added
separately. We're calling mypy by way of a script, as this allows us to
store a list of files that we have converted while we're in the process
of adding type annotations where necessary.
Signed-off-by: Stephen Finucane <email@example.com>