Save githash for print_diag when using plot_fluxparam.
Save githash for print_diag when using plot_fluxparam.

I think this makes sense because print_diag does all the heavy lifting.
Updates to plots in plot_fluxparam will be saved when I use export_fig
anyway.

dcherian/eddyshelf,dcherian/eddyshelf,dcherian/eddyshelf