Current behavior:

pygenesys.utils.growth_model currently as two growth methods implemented

• linear
• exponential

Desired behavior:

A third optional growth method should be added called logistic. Logistic growth is similar to exponential growth
but levels off when a "population" or "demand" approaches a maximum value.

Guidance:

The method should be added to growth_model.py as a new function called logistic_growth and then add the method to the dictionary in choose_growth_method.

A description of logistic growth modeling can be found here.