Integration tests for hosts client

1.Added a mock library called httpretty.
2.Added tests to list and get hosts.

Change-Id: Id8936daa15cd646c800a530e2773914a42eeb6ca
Added Hypervisor Client and Model

Created a hypervisor client and model

Change-Id: Ibbcdaa97682c27f9b33fac5b731b70f3f792ddb1
Merge "Integration tests for hosts client"
Adding __init__.py in hosts_api.models

Change-Id: Ia84c185ba5f921d6ebadfa79196733edcf5facac
Added instance actions client and models

* Added basic client and model for instance actions
* Added user id to user config to be used in action
  validations

Change-Id: Ib301473a618c00ebda8193e36ced4976226a8d12
Added quotas model and client

1. Refactored Integration tests to have a fixture
2. Refactored hosts integration test to adhere
    to new framework.
3. Added unit tests for quotas and quotas request
    model.

Change-Id: I5723d3ff19b22227c61adca08f0fdd977a09e3b9
Refactoring the hypervisor model

Updated the serialization and deserialization structure.

Change-Id: Ia8f776699021f575fc374dfbd7a955a83ad95160
Merge "Refactoring the hypervisor model"
Merge "Added quotas model and client"
Fixing sudo user issue with virtual environments.

Change-Id: I828a17e6675c21a8eab0fc4f2afbd70487a5f83f
Blockstorage behaviors refactor and versioning
* Implemented exception-raising behaviors for volumes_api.
* Removed blockstorage provider.
* Added volume and snapshot statuses model.
* Refactored response models.
* Versioned volumes_api as v1, added stub for v2
* Cleaned up rax auth extensions
* Fixed VolumeTypeList model
* Added default_volume_type config property

Change-Id: I706fb867e9d892dceb994eeb9052d45d9c649fbf