split infection code into limited and total
changed limited infection to take in starting node as input
added limited infection explanation to readme
updated running instructions in readme
added run instructions to readme
limited infection now takes any edgelist, made dummy edgelist for testing purposes
updated edge list reading in limited infection
added exception handling for running on command line
modified dummy edgelist for testing
updated readme
added descriptive comments to user and graph classes
updated readme with info on dependencies
updated visualization function