Support snapshot vesion 2

[tochi-y]

Importing app-minimal-clone.zip in current personium-core version, the following error is occurred.

POST https://test-tochi.stg-demo.personium.io/__import
{"Name": "app-minimal-clone"}

400 Bad Request
{
  "code": "PR400-MC-0003",
  "message": {
    "lang": "en",
    "value": "Version of the snapshot file is invalid. Expected [2] but was [1]."
  }
}

Needs to support snapshot version 2.