Minor version bump

* Make sure docker-api works with frozen string literals

Minor version bump

* Increase excon version requirement to v0.64.0
* Use excon interface for middleware parameters

Minor version bump

* Fix dockerignore logic
* Fix podman check in Docker::Exec

Minor version bump

* Add podman support

Patch version bump

* Streaming logs request should be idempotent

Patch version bump

Minor version bump v1.34.0

* Implement prune
* Require newer excon to get rid of Host issue
* Use MultiJSON in favor of regular JSON
* Don't mutate options in Docker::Container.create

Patch version bump v1.33.6

Make Image.search respect credentials

Patch version bump

* Fix base64 encoding for auth headers
* Add docker 1.12 and 1.13 to travis
* Add missing tag parameter for `Image.get` call at the end of
  `Image.create`

Patch version bump v1.33.4

Expose original format of `top` endpoint