Paper: Scientific Computing with SciPy for Undergraduate Physics Majors (Bill Baxter)

Paper for SciPy2014 proceedings.  I'm a GitHub and rst novice so this should be interesting!  I'm having two issues: first, I don't see how to get my figure file onto GitHub.  Second, I'm clearly doing the reference labels for tables and figures incorrectly.  Hopefully someone can point me in the right direction!
One of the major arguments against using Excel is that it is very difficult to test and prone to off-by-one etc errors: http://lemire.me/blog/archives/2014/05/23/you-shouldnt-use-a-spreadsheet-for-important-work-i-mean-it

Does this have any traction as an argument in your courses?