Main Dockerfile should be aligned to Polly service

[clintkitson]

https://hub.docker.com/r/emccode/polly/~/dockerfile/

It looks like updates to the Dockerfile recently shifted the Dockerfile from being an image that helps run Polly to an image that helps build Polly.

Something like docker run emccode/polly should enable someone to run Polly as a service.

[davidvonthenen]

@clintonskitson doing a very very quick pass at the original dockerfile, it looks like the original only built the polly using make based on the last CMD line in the file. It did expose ports, but says nothing about running.

We can definitely split the functionality to run versus build, but if we change this Dockefile to run the stable version of polly, what storage driver should be configure for polly to use in this Docker image? The vagrant file made the selection obvious since its in virtualbox... not so much for running in docker considering the limited selection for drivers that are available for 0.4.X.

[davidvonthenen]

Doing another pass at the history of the file and it looks like the Dockerfile originally did run as opposed to build....

https://github.com/emccode/polly/blob/394149d9f80a3f6ef3f24684f6063c363c8249f9/Dockerfile