Added visualization code

This includes a small change to the contagion.py file that makes it
easier to extract the model data.  I'm not attached to doing it this
way.
Revert "Added visualization code"

This reverts commit d6f7d285470afd873a091c33b78c95fcdc8cd687.
Revert "Revert "Added visualization code""

This reverts commit a5f96a3b69ba865d226cac4153f5e4c62fca9738.
Revert "Revert "Revert "Added visualization code"""

This reverts commit 47b0b4eee3a1f96377483c65f2bfac854f787dd1.
Revert "Revert "Revert "Revert "Added visualization code""""

This reverts commit 92f9cb00aeea0ed8eaf8a36e47728b62fa5af9dc.
Removed old pickling code
Added short note about running code locally
Merge pull request #1 from somodernized/new

New