Bugfixes and Xcode 11 Support

Released on 2019-10-25. All issues associated with this milestone can be found using this filter.

Fixed

• Issue where Carthage was unable to build SQift due to schemes requiring test suite compilation.
  • Fixed by William Thompson in Pull Request #28.
• Issue in Xcode project Documentation group where links were invalid and README links were broken.
  • Fixed by James Eisenhauer in Pull Request #30.
• Compiler warnings in Function.swift picked up by Xcode 11.
  • Fixed by Christian Noon in Pull Request #31.