ANN: SPAN docker images

[Karl MacMillan <karl@xxxxxxxxxxxxxxxxxxxxxx>]

SPAN - the Jupyter notebook environment for policy analysis on top of 
setools - is kind of a pain in terms of dependencies. So I made a docker 
image to make it easier. Now you can just use:

|docker run -p 8888:8888 -v $(pwd):/home/span/SPAN/work 
bigbadwolfsecurity/span|

|That will start SPAN with your current directory mounted and available 
for Jupyter with all of the SPAN dependencies loaded. More information 
can be found at https://github.com/BigBadWolfSecurity/span-docker.|

|Karl
|