//The "hard stuff" (pan,zoom, drag, drop) comes from Mike Bostocks block #4063570 and is not my work

In this exercise you need to take an array of tabular data and generate a tree structure which will act as an org chart.
The only information you have in the tabular data is the associate name, and his/her manager's name.
The root of the tree will have an undefined value for manager.
The hierarchical representation of this data could be used in something like a D3 dendrogram to visualize your organizational structure.

** Edit as of June 28th 2016 this block is a lot less interesting
** D3 v4.0 introduced d3.stratify() which converts tabular data to hierarchial data in one clean function
** Check it out: https://github.com/d3/d3-hierarchy#stratify