Pfla

Major overhaul of the package:

- modified package structure
- pure python
- mtcnn and face-alignment for image processing
- reduced dependencies
- simple cli usage

This release comes after both reviewers have given their feedback and approved the software package for publication in JOSS.

Official post-review release of the pfla package for facial landmark analysis.

This release will serve as the initiate version for the JOSS reviewing process.