Ticket subclasses: incident, problem, question and task
Tickets must have a requester (User). Any user can request tickets.
Tickets can be assigned
initial user importer
Added Formatters for various types
use private method instead of class
each importer needs to define #import_raw
add support for group(s)
Agents have Groups
Use Formatter#formatted to save string to User table
rake import:agents
always save email downcase