Inconsistent type of response field in /conversations.open

[pluehne]

Description

In the specification of the Web API endpoint /conversations.open, the type of the created field in the response is string, while it is integer in definitions/objs_conversation. I think this should be corrected to integer for consistency. The Slack API documentation also shows this field to be of integer type.

What type of issue is this?

• [x] bug
• [ ] enhancement (feature request)
• [ ] question
• [ ] documentation related
• [ ] testing related
• [ ] discussion

Requirements

• [x] I've read and understood the Contributing guidelines and have done my best effort to follow them.
• [x] I've read and agree to the Code of Conduct.
• [x] I've searched for any related issues and avoided creating a duplicate issue.