* Add FileDownloadDelegate for simple file downloads
* Add testFileDownload to the allTests array
* Fix formatting
* Fix compatibility with Swift 5.0
* Add doc comments, update README.md
* Refine FileDownloadDelegate description in README
* Bump NIO version, remove weak self, cleanup test
* Fix formatting issues in a doc comment
* Create separate Progress struct, async open file
* Create an ad-hoc EventLoopGroup for opening a file
* Move file opening code to `didReceiveBodyPart`
* Fix linter error in FileDownloadDelegate.swift
* Fix wrong future assignment in FileDownloadDelegate
* Fix Swift 5.0 return statement compatibility
* Fix linter warning
* Fix Swift 5.0 return statement compatibility
* Remove redundant `write` function
* Add negative test case and separate testing endpoint
* Add missing testFileDownloadError to the manifest
Max Desiatov