Load all components of the Starsim environment, including: ss (all
Starsim functionality); NumPy (np), pandas (pd), Sciris (sc), and
Matplotlib (plt), for additional Python functionality; and some of
the core Starsim classes (e.g. Sim, Disease). After installation,
this is the only function that needs to be called from R-Starsim;
everything else is accessed via ss.