Spacing between brace and closure parameters

[maveric94]

New Issue Checklist

• [ ✔️] Updated SwiftLint to the latest version
• [ ✔️] I searched for existing GitHub issues

Rule Request

Rule to check spacing between opening brace of closure and following parameters and parameters and  'in' keyword. Maybe it can be added to closure_parameter_position rule.

Environment

• SwiftLint version 0.25.1

• CocoaPods

• Xcode version 9.3

// This doesn't triggers a violation:
let test: (Bool) -> Void = {          obj           in
}

[reggian]

The initial space between opening brace and first closure parameter could also be added to closure_spacing rule (which currently handles only single lined closures).