0.21.0: Sylvester J. Pussycat Sr.

Breaking

• SourceKitten now requires Swift 4.0 or higher to build.
  JP Simard

Enhancements

• Make all SwiftDeclarationAttributeKind cases available no matter
  which version of Swift was used to compile SourceKitten.
  Marcelo Fabri

Bug Fixes

• Fix issue locating libsourcekitdInProc.so on some Linux distributions.
  Mike Hovan
  #513