Created Player, updates to Senate,

created the (for-now) empty class Player just to expound on the changes
made during my last committ.

Added working toString methods to Senate and State classes
Added working constructors to those classes
Worked in error handling to State class during construction (what if
they try to create a State that is not actually in the Union?)
Learning this error handling and implementing the try-catch flowing in
Driver is what caused most of the 2-hour delay