Change cover photo

**Brief description:**

- Add a new profile cover photo.

**Endpoint：**

- `https://www.mywebsite.com/api/v1.0/photos_cover_add`
  
**Method:**

- POST / GET

**Parameter:**

|Parameter name|Required|Type|Explain|
|:----    |:---|:----- |-----   |
|api_key_token |Yes  |string |Your API key   |
|userphoto|Yes|array| A image file.
|guid|Yes|integer| User `GUID` for which you wanted to change photo.|

**Example Response **

``` 
{
    "merchant": "Open Source Social Network",
    "url": "http:\/\/www.mywebsite.com\/",
    "time_token": 1569325087,
    "payload": {
    	"guid": 123,
        "user": {
            "guid": "1",
            "first_name": "System",
            "last_name": "Administrator",
            "fullname": "System Administrator",
            ...
            ...
            ...
        },
    },
    "code": "100",
    "message": "Request successfully executed"
}
```

**Return payload parameter description **

|Parameter name|Explain|
|:-----  |-----|
|guid| Contains newly added photo `GUID`|
|user| Contains the details of photo owner user|

** Remarks **
- Error `200` will arrise in case it failed.