x-logo is broken

[kplachkov]

Describe the bug
Using // @x-logo ... will result x-logo outside the info scope.

To Reproduce
Steps to reproduce the behavior:

1. Go to main.go
2. Add:

// @title Example API
// @version 1.0
// @description API
// @x-logo {"url": "https://example.com/img.png", "backgroundColor": "#000000", "altText": "example logo", "href": "https://example.com/img.png"}

3. Run swag init
4. Go to docs/swagger.json and docs/swagger.yaml

swagger.json

..................................
    "x-logo": {
        "altText": "example logo",
        "backgroundColor": "#000000",
        "href": "https://example.com/img.png",
        "url": "https://example.com/img.png"
    }
}
<=========================== EOF

swagger.yaml

..................................
swagger: "2.0"
x-logo:
  altText: example logo
  backgroundColor: '#000000'
  href: https://example.com/img.png
  url: https://example.com/img.png
<=========================== EOF

Expected behavior

swagger.yaml

.....................
info:
  contact: {}
  description: API
  license:
    name: Apache 2.0
    url: http://www.apache.org/licenses/LICENSE-2.0.html
  title: Example API
  version: "1.0"
  x-logo:
    altText: example logo
    backgroundColor: '#000000'
    href: https://example.com/img.png
    url: https://example.com/img.png
.................

swagger.json

{
    "swagger": "2.0",
    "info": {
        "description": "API",
        "title": "Example API",
        "x-logo": {
            "altText": "example logo",
            "backgroundColor": "#000000",
            "href": "https://example.com/img.png",
            "url": "https://example.com/img.png"
        },
        "contact": {},
        "license": {
            "name": "Apache 2.0",
            "url": "http://www.apache.org/licenses/LICENSE-2.0.html"
        },
        "version": "1.0"
    },
.................

Your swag version
v1.6.7

Your go version
go version go1.14.6 linux/amd64

Desktop (please complete the following information):

• OS: Ubuntu
• Browser: chrome
• Version: 84

[Nerzal]

I already wrote a fix for that + some additional sugar :)
Just needs to be merged :)