### Fixed
- Fixed `#[instrument]`ed async functions not compiling on
`nightly-2019-09-11` or newer (#342)
### Changed
- Significantly reduced performance impact of skipped spans and events
when a `Subscriber` is not in use (#326)
- The `log` feature will now only cause `tracing` spans and events to
emit log records when a `Subscriber` is not in use (#346)
### Added
- Added support for overriding the name of the span generated by
`#[instrument]` (#330)
- `log-always` feature flag to emit log records even when a `Subscriber`
is set (#346)
Signed-off-by: Eliza Weisman <eliza@buoyant.io>