Swift 5

This release is simply project modernization for Swift 5.

The Cleaner

This release introduces adds a new clear() method that adds a method for deleting Default objects.

Thanks @nitrag for putting this together!

To the point

Summary

The release's focus is about shortening the read / write method names and adding support for having a default
value for when the value being read is currently not stored in the users defaults.

Changes

• Writing an object to UserDefaults with Default is now accomplished with: write() or write(withKey:)
• Reading an object from UserDefaults is now accomplished with read() or read(forKey:)
• defaultValue has been added to the protocol, the default implementation returns nil can be customized
  to return a default value when nothing exists in defaults.

@Cyberbeni Thanks so much for the pull request! Great work! 💯

Codable all the things!

This is the initial release of Default!