add test to check configuration parsing is as expected, before adding new default functionality
ideas on new config file format
helper script for creating test data
New config parser, with test data.

* Config now is Org level.
* Has multiple vDCs
* Has 'vapp_sets' - groups of vapps with same role/defaults
* Default values are settable at org, vdc, and vapp_set
* Also changed :disks key to :extra_disks
  * better reflects that it does not include system disk
* adjust interface of Vapp to reflect that vdc and templates are now per-vapp

Tidy up require statements
Introduce deprecation handler

* help users know about new config syntax
* Also fix up a broken example config
bump version to 0.1.0 since input format changes
fix to integration test - missed commit of change to Vapp interface
missed commit -- per vapp @vdc_name
Merge pull request #8 from alphagov/configuration_improvement

Configuration improvement - allow defaults at each level, and introducing 'vapp_sets'