Comments on descriptions in Chapter 2

[Michael Zingale]

1. In the statement of the problem at the top, there is no mention of boundary conditions. Likewise, in writing the tridiagonal matrix for the solution, we would need to use the boundary conditions to get the form for the first and last row.

   Boundary conditions are discussed later, but they should be foreshadowed at the start.

2. scipy is a dependency here – this should be noted in the README.md

[Christopher Thomas DeGroot]

These have now been addressed.