Add missing figures.
Merge branch 'master' of github.com:ketch/HyperPython

* 'master' of github.com:ketch/HyperPython:
  Remove long tutorial.
  Updates to all lessons.
Test math formatting for nbviewer.
Create README.md
Update README.md
Update README.md
Add a missing link to Lesson 4.
Update README.md
Merge pull request #3 from IanHawke/master

Add a missing link to Lesson 4.
Remove clawpack install instructions in lesson 4.
Move lessons to root directory so figures always show up.
Update README.md
Update README.md
Use local Lax-Friedrichs flux in lesson 3 part 2.
Update README.md
Update paths to reflect new directory structure.
Merge branch 'master' of github.com:ketch/HyperPython

* 'master' of github.com:ketch/HyperPython:
  Update README.md
Remove non-working Mathjax stuff.
Update README.md