Update ipynb files

[skyfielders]

Update ipynb files

[erinspace]

Working on Asteroids.ipnb!

[chrisgilmerproj]

Working on Hertzsprung-Russell.ipynb

[chrisgilmerproj]

Working on Axis-Wobble.ipynb

[erinspace]

working on Interactive-3D-Earth-Satellites.ipynb

[chrisgilmerproj]

Working on Interactive-3D-Solar-System.ipynb

[chrisgilmerproj]

Working on Stars.ipynb because I'm stuck on Interactive-3D-Solar-System.ipynb

[erinspace]

Moving on to Stellar-Color-Index.ipynb because I also got stuck on Interactive-3D-Earth-Satellites.ipynb with the error:

This program needs access to the screen.
Please run with a Framework build of python, and only when you are
logged in on the main display of your Mac.

[chrisgilmerproj]

Working on Javascript-integration.ipynb

[chrisgilmerproj]

I believe the interactive books named Interactive*.ipynb need this addition to them:

import os
os.environ['ETS_TOOLKIT'] = 'qt4'

This advice was grabbed from the example at: http://docs.enthought.com/mayavi/mayavi/auto/example_qt_embedding.html

[chrisgilmerproj]

This is old enough its probably worth closing.