adds Iteration model
Moved pt import code to Burndown
Remove all traces of VCR.

VCR is not the right tool for the job in this project.
Remove VCR dependency
Start with cleanup
Revised models
Burndown JSON decorator

 * Use draper to render JSON for a burndown in Google Chart format.
 * Move to FactoryGirl because Fabrication had some trouble with
   nested has_manies.
Add feature for updating PT data.
WIP - Add PivotalIteration for support.
Import PivotalTracker methods.
updates seeds.rb for data model changes
Remove commented/removed code

[ci skip]
Refactor import code.

 * Move iteration create/update to private method.
 * Use better variable names.
Merge pull request #13 from kabisaict/fix_importing_and_data_storage

Fix importing and data storage