Generate the acs engine JSON file from the UI

[julienstroheker]

From #1 we will generate the acs-engine .json file such as :

{
  "apiVersion": "vlabs",
  "properties": {
    "orchestratorProfile": {
      "orchestratorType": "Kubernetes"
    },
    "masterProfile": {
      "count": 1,
      "dnsPrefix": "",
      "vmSize": "Standard_D2_v2"
    },
    "agentPoolProfiles": [
      {
        "name": "agentpool1",
        "count": 3,
        "vmSize": "Standard_D2_v2",
        "availabilityProfile": "AvailabilitySet"
      }
    ],
    "linuxProfile": {
      "adminUsername": "azureuser",
      "ssh": {
        "publicKeys": [
          {
            "keyData": ""
          }
        ]
      }
    },
    "servicePrincipalProfile": {
      "clientId": "",
      "secret": ""
    }
  }
}