And to python interface

* Add ability to access a single departure term in a multi-fluid model

* Bump version to dev

Problem: compile-time time arguments remapped to runtime arguments, in future the runtime arguments should come after the model

* Add methods for calculation of pure fluid critical points

* Pass the template arguments along

* Expose the values and Jacobian

Closes #8

* Add partial molar volume as a possible output

* And expose to python

* A fully encapsulated library wrapper with C++ interface

* Refactor types.hpp to hide the big headers in a macro conditional section

To check whether you have gotten to the critical point

* Split out reducing and mutants to their own headers

* Remove unused function

Refactor to avoid duplication

Add test and expose in Python

Based largely upon: https://pubs.acs.org/doi/abs/10.1021/acs.iecr.1c04703

TODO: apply polishing in another variable if constant composition polishing fails