---------------------
Improvements
- Test against Python 3.4 using Travis
- Build with `pyproject.toml` and `setuptools`, removing old `setup.py`.
- Convert testing library to `pytest` (from `nose`).
API changes
- Properties on `CameraModel` (e.g. `cam.M`) are deprecated and will
be removed in a future release.
- Intrinsic parameter matrix is normalized upon loading in
`CameraModel._from_parts`, which is called by most constructors.
- If an input calibration has a non-normalized P matrix and a
rectification matrix, a warning is given as this case is not well
tested and the behavior should be considered undefined.
Bugfixes
- Mirroring and flipping cameras with skew, distortion, and
rectification work now.