Use entry points instead of scripts in setup.py.

[moorepants]

This would allow a noarch build in conda forge (might also the the correct way to do it).

conda-forge/yeadon-feedstock#8

[moorepants]

Here is the one from skijumpdesign:

 entry_points={'console_scripts':
                  ['skijumpdesign = skijumpdesign.app:app.run_server']},

We have logic in bin/yeadon so that would need to be moved into the yeadon package. Could do bin/yeadon->yeadon/app.py then use the above entry point.