schema: add AzureStack schema
"aliyun",
"amis",
"azure",
+ "azurestack",
"build-url",
"digitalocean",
"gcp",
"aliyun",
"aws",
"azure",
+ "azurestack",
"dasd",
"digitalocean",
"exoscale",
"title":"Azure",
"$ref": "#/definitions/artifact"
},
+ "azurestack": {
+ "$id":"#/properties/images/properties/azurestack",
+ "type":"object",
+ "title":"AzureStack",
+ "$ref": "#/definitions/artifact"
+ },
"digitalocean": {
"$id":"#/properties/images/properties/digitalocean",
"type":"object",
