Plot viewing procedures differ in the Download Antarctica datasets tutorial

[PennyHow]

Description of the desired feature: The Download Antarctica datasets tutorial does not contain the same plotting procedure for viewing each of the generated figures (compared to the other tutorials). Shouldn't you need a figure priming function after maps.plot_grd(grid)? Perhaps something like this:

maps.plot_grd(grid)
fig = maps.plot_grd(grid)
fig.show()

[mdtanker]

Good catch. It seems Jupyter notebooks will automatically show the figure either way, but to be compatible with running from the terminal, I will add in your correction as part of #195.