Move plots into the main module

7 add missing parameters (#14)

Added missing parameters:
- bth for setting the maximum branch count
- nmiss for limiting the maximum number of missed detections in a track
Added unit tests
Added trackvis: A module for track plotting using matplotlib
Added new sample data and plots

Improve MWIS speed through pivoting (#13)

* Keep pivoted BK throughout, attempt to find best candidate for pivoting.

Update CITATION.cff

STYLE: Reformat file structure for PyPI package