prove basic render for graph (stock data)

snapshot graph updated to use actual node-role relationships

use ID instead of string
correct BDD test from VL changes to node_role

address test failure
tweak node labels on graph
update simulator instructions
improve formatting
Merge pull request #684 from cloudedge/pull-req-master-ec50262ec7fe8599260a9739fd3a8a7ac571c838

https://github.com/crowbar/barclamp-crowbar/pull/684

Merged by devtool for VictorLowther