Added Dockerfile and configuration files under the
new `docker` directory to build a Swift All in One container
image.
The primary goal of this container image is to provide
application developers with a Swift/S3 endpoint that can be
tested against during the development cycle.
Added Zuul jobs to build docker container
Change-Id: Ib10975a1862a4fa8c4eeaba139837cf1f22b272a