GMAT validation: wrappers and tests

[jorgepiloto]

I am trying to solve for https://github.com/poliastro/poliastro/issues/740 and therefore a comparison against another software is required. GMAT only requires a simple *.script file to generate an output *.txt file where orbit data is stored.

My plans the following:

• [ ] Create a gmat/core, gmat/scripts and gmat/results folders were GMAT binaries, scripts and output data files are stored respectively
• [ ] By simply running a make gmat_tests from a custom Makefile, scripts are runned and output files are generated
• [ ] An specific format is defined in the *.script files when generating the *.txt output file, so a Python reader is specifically designed to extract interesting data from those files
• [ ] Finally a tests directory makes use of those readers and data files to run the poliastro validation

What do you think about this draft idea? May be too hard to include GMAT binaries inside the repo?

[astrojuanlu]

My only concern is storing the GMAT binaries, I would strongly advise against it. In my view, we should only store here the scripts, and describe somewhere how to install the software.

The rest sounds about right! The most painful thing will be reading the data from the output .txt. Perhaps there's a way to return a more structured data format.