Implement Riemann Solver

[MatthewGrim]

This issue documents the work I undertook to write my own Riemann Solver based on the work in Toro. This was an academic exercise to help me further my understanding of the initial value problem and how it can be solved in hyperbolic differential equations and applied to Euler's equations to solve CFD problems.

Much of the work follows that in Chapter 4 of the book Riemann solvers and Numerical Methods for Fluid Dynamics by E. Toro