This us the implementation of the HPP_model, using prime number mapping.
This has 4 files.
GasLattice.jl : is the main file, and contains the main function that outputs by default a heatmap.
GasLatticePressure.jl : Computes the particles hitting the border at one time. And returning an array. This is the
			Function used to produce the pressure plot. 
mapping_functions.jl and pressure_functions.jl : Secondary functions. Read the comments here first.