Swagger API: Adding the env.json

This is the Swagger definition file for environment variable.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Swagger API: Adding the env.json to the api-docs

Adding the env.json to the api-docs so it will appear in the Swagger UI
GUI.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Http Server: Adding the env API implementation

Adding an implementation for environment variable support.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Http Server: Call env::init from main

Adds a call to initialize the env implementation to main.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Http Server: Add tests for environment variable

Add a test to set and retrieve of an environment variable.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>