What Swift version(s) do you rely on for Kitura? (currently or in the near future)

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* 1. What versions of Swift do you rely on for Kitura on Linux? (currently or in the future)

Swift 5.3

Swift 5.2

Swift 5.1

Swift 5.0

Swift 4.2

Swift 4.1

Swift 4.0

Additional comments?

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* 2. What versions of Swift do you rely on for Kitura on macOS? (currently or in the future)

Swift 5.3

Swift 5.2

Swift 5.1

Swift 5.0

Swift 4.2

Swift 4.1

Swift 4.0

Comments?

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* 3. Anything else you'd like to tell the community maintainers? What other interesting ways are you using (or planning to use) Kitura?

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* 4. Care to leave your name & contact info if we have follow up questions?