tower 0.3.1

Tower is a library of modular and reusable components for building robust clients and servers.
Documentation
# 0.3.1 (January 17, 2020)

- Allow opting out of tracing/log (#410).

# 0.3.0 (December 19, 2019)

- Update all tower based crates to `0.3`.
- Update to `tokio 0.2`
- Update to `futures 0.3`

# 0.3.0-alpha.2 (September 30, 2019)

- Move to `futures-*-preview 0.3.0-alpha.19`
- Move to `pin-project 0.4`

# 0.3.0-alpha.1a (September 13, 2019)

- Update `tower-buffer` to `0.3.0-alpha.1b`

# 0.3.0-alpha.1 (September 11, 2019)

- Move to `std::future`

# 0.1.1 (July 19, 2019)

- Add `ServiceBuilder::into_inner`

# 0.1.0 (April 26, 2019)

- Initial release