Upper cases in x-tentions dont work in general API info

[Janwillemtv]

Describe the bug
I have run into an issue when declaring tagGroups in the general API information.
When using // @x-tagGroups [{"name":"General","tags":["lanes","video-recommendations"]}]
it gives the error annotation @x-taggroups need a value

When looking into it it seems you already fixed this issue for the operation side of it, but not for the general API parser.
What happens is that the attribute gets extracted and lowercased from the commentline

attribute := strings.ToLower(strings.Split(commentLine, " ")[0])

so in this example it becomes @x-taggroups.

In the switch case for ParseGeneralAPIInfo in parser.go the default action tries to split the comment using this lowercased attribute:

default:
prefixExtension := "@x-"
if len(attribute) > 5 { // Prefix extension + 1 char + 1 space  + 1 char
	if attribute[:len(prefixExtension)] == prefixExtension {
		var valueJSON interface{}
                // HERE IS THE ISSUE
		split := strings.SplitAfter(commentLine, attribute+" ")
		if len(split) < 2 {
			return fmt.Errorf("annotation %s need a value", attribute)
		}

For camelcased @x-tentions (or any x-tentions using Upper case) it always returns an error because it tries to split the commentLine using the lowercased version of the attribute, which does not match because it still contains upper cases.

It works when using // @x-taggroups (so all lower case) but this does not give a working swagger doc with camelcased x-tentions.

To Reproduce
Steps to reproduce the behavior:

1. Use // @x-tagGroups [{"name":"General","tags":["lanes","video-recommendations"]}] as a general API doc
2. run swag init
3. See error annotation @x-taggroups need a value

Expected behavior

1. Use // @x-tagGroups [{"name":"General","tags":["lanes","video-recommendations"]}] as a general API doc
2. run swag init
3. swagger.yaml doc should contain:

x-tagGroups:
  - name: General
    tags:
      - lanes
      - video-recommendations

Your swag version
e.g. 1.7

Your go version
e.g. 1.13.8

Desktop:

• OS: linux/ubuntu
• Browser: chrome
• Version: 89

[ubogdan]

I will take a look into it any time soon.

[ubogdan]

The fix will be released with v1.7.4