Cyvlfeat

- Python 2.7 no longer supported as it is end of life and already conflicts with upgrades such as changing to miniver over versioneer (used for managing the auto-releases)
- Thanks to hubutui, simmimourya, AlexisMignon and YohaiDevir for their contributions - particularly simmimourya for all the contributions in improving feature parity with the Matlab vlfeat
- Also note a major bug fix in the HoG code for color images (31) and a change in behavior for the Fisher model in expectations for the data matrix shape (20)

Expose the HOG method and enable Python 3.5 builds.

Thanks to williamkreamer, cyvlfeat now supports the `vl_fisher_encode` method.

Also, change the order in which data is processed to try and speed everything up.