This can be used for avoid "Test::Unit::AssertionFailedError" error in `libxpc.dylib` on calling `sourcekitd_send_request_sync` in sandbox environment.
This bumps the minimum version required to build SwiftLint to 4.2. The primary motivating factor to drop support for Swift 4.0-4.1.x is that SwiftLint now uses CryptoSwift, which requires 4.2.
* Add changelog entry
* Remove --allow-warnings flag from CocoaPods commands
* Update CryptoSwift to 0.13.0
* Migrate to Swift 4.2
* Remove CircleCI tests for Swift < 4.2
* Update English and Chinese README
Korean README doesn't yet have a version table like this.
* Update gems
* Add changelog entry for fixed compiler warnings
* Update CocoaPods to 1.6.0.beta.2
To work around https://github.com/CocoaPods/CocoaPods/issues/7708
* Add UnusedPrivateDeclarationRule
* Temporarily disable UnusedPrivateDeclarationRule tests on Xcode 10
So we can merge UnusedPrivateDeclarationRule without having to wait
for CircleCI to update its Xcode 10 version.
Norio Nomura