Create an app which uses actors to calculate and print to console the
number of prime numbers equal to or less than a user-entered number.
Update a constant to have the lowest visibility needed for the code it's
used in.
Improve comment of section of app which reads in user input and
starts the processing of it.
Add todo list for app as comment in app main class.
Update app to make the actor which receives requests from the app act as
more of a supervisor, dispatching work in a more intelligent manner and
processing the results from the child actors.