Added 'ag list' command with unit tests. Implementation with integration test to follow.
Fixed broken server describe command, and broken functional tests.
Added ag create command.
Add unit test for server describe.
Added 'vnet list' and 'vnet create' and unit tests.
Update README.md

Added sections for new ag/vnet list/create commands.
Add functional test for ag and vnet.
Fix whitespace in README.md.
Merge pull request #127 from MSOpenTech/vnet-ag

KNIFE-427: Add support to create virtual networks and affinity groups