5.1.0

Breaking

• None.

Enhancements

• None.

Bug Fixes

• Change how empty strings are decoded into nullable properties.
  key: "" previously decoded into
  struct Value: Codable { let key: String? } as Value(key: nil)
  whereas after this change it decodes as Value(key: "").
  This could be a breaking change if you were relying on the previous
  semantics.
  Liam Nichols
  #301

• Fix parsing of unquoted URLs into Strings.
  Honza Dvorsky
  #337