Minor version bump v1.23.0

Add support for a wait timeout on `Container#exec`

Patch version bump

Don't retry when waiting for a container

Patch version bump (v1.22.3)

Use same connection when running Container#exec

Patch version bump

Enable passing of a user to `Docker::Container#exec`

Patch version bump

Fix `Image.save` in Ruby 2.2

Minor version bump

* Better streaming logs support for long running processes

Patch version bump (v1.21.4)

* Enable retries with Container#wait

Patch version bump (v1.21.3)

* Enable use of docker cache

Version bump (v1.21.2)

* Timeout error doesn't have a response

Patch version bump (v1.21.1)

Make error messages pertain to the errors