Added:

- `std::error::Error` as a new primitive type (#277)
- Support for mixing key-value fields and `format_args` messages without
  curly braces as delimiters (#288)

Changed:

- `tracing-core` dependency to 0.1.5 (#294)
- `tracing-attributes` dependency to 0.1.2 (#297)

0.1.5 (August 16, 2019)

Added

- `std::error::Error` as a new primitive `Value` type (#277)
- `Event::new` and `Event::new_child_of` to manually construct `Event`s (#281)