Build and instructions

[RussTorres]

We've improved the build process, but need to document some odd things and improve the docker experience.

When running from the continuumio/miniconda3 docker image these steps let me install:

apt-get update 
apt-get install -y build-essential libgl1-mesa-glx

python setup.py install
python setup.py install

alternatively

apt-get update
apt-get install -y libgl1-mesa-glx

conda install -y -c conda-forge fast-histogram
python setup.py install

The docker file we are using does a much more complicated installation that is likely unnecessary (particularly since we are converging on opencv-python or opencv-python-headless as a dependency). This Dockerfile, however, is based on a very old image that has the render java code built in it. This should not be necessary.