Create a push token of the user, if there is not any. And return it

Url: https://api.playkey.net/rest/PlaykeyAPI.svc/user/pushtoken

HTTP Method: POST

The following is an description request Json body:

lang - Display language
api_version - API version (default equal 1)
ga_clientId - Google Analytics ID
token - Authentication token

The following is an example request Json body:

{
    "lang": "lang",
    "api_version": 1376297253,
    "ga_clientId": "gaclientid",
    "token": "token"
}

Description of how to response:

error - Error information
    code - Error code. Error 0 - no error
    message - Error message. Empty if none

The following is an example response Json body:

{
    "error": {
        "code": 0,
        "message": "string"
    },
    "push_token": null
}

The following is an example response Xml body:

<result xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
  <error>
    <code>0</code>
    <message>string</message>
  </error>
  <push_token i:nil="true" />
</result>