Added Snapshot.scala
Started doing the Snapshot tests, modified the Graph.countNodes() so that it counts only the nodes of type person, continued the Snapshot class dev.
Added the fillShortestPaths() method for the Snapshot class.
Added betweenness and closeness calculation, and some tests.
Added comments documentation to Snapshot class.
#21 added the README documentation of the v0.1.1
Modified build.scala to match version and product name
Adapted to new census api class names
Version in build.scala and added instructions on how to assembly the jar in the README.
Bug fix.
Project name fix.
Added stress (commented).
Added aspTime (all shortest paths time) attribute to Snapshot.
Added TODO in README.md