Test for Doxygen Warnings

[jackdunger]

• Clone the PR repo
• build doxygen, and check the log for warnings
• a single warning fails the test
  --> this should not be merged until the planned doxygen clean-up, as there are currently >5000 warnings..
• dependent on the char_test PR for changes to task.py

[mastbaum]

I think this should be os.path.join.

[mastbaum]

Works for me modulo the os.join, though it fails with an impressive 5579 warnings on our repo. So maybe we should wait until @straitm updates to only try doxygen on certain subdirectories?

[jackdunger]

Thanks for looking at this. I've just fixed the os.join.
Agreed, best to wait until the doxyfile's changed and the existing warnings are gone,