Restructured Dockerfile to produce a smaller image

Combined multiple RUN commands with additional cleanup to yield a
smaller image when the build is complete.

Followed considerations for optimizing your dockerfile based on blogs:
http://blog.tutum.co/2014/10/22/how-to-optimize-your-dockerfile/
http://jonathan.bergknoff.com/journal/building-good-docker-images

Conflicts:
	Dockerfile
Modified entry_point to run hub/node combination

In my attempts to have another container utilize this as a Remote
selenium driver, I had issues with only being allowed to make requests
from within the container. By running both a hub and node you will be
able to have other containers use this container for driving a browser.
Therefore your test container does not have to derive from this image.

For example if you build a NodeJs, Python, or Java application you can
run your server and tests from your application's container with a
browser from this one.

However, if you still wish to derive from this container and make calls
to within itself you are also free to do so.
Merge pull request #3 from mtscout6/hub-node

Restructured Dockerfile for smaller image and allow for non-localhost connections