Convert default images to using conda

[semperstew]

• Do you want to request a feature or report a bug?
  Feature

• What is the expected behavior?
  conda install <random_package_name_here>

• What is the motivation / use case for changing the behavior?
  Use conda environments to allow users more freedom to install additional/special packages. This may even help users install additional R packages since R can be installed into a conda environment.

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. stackoverflow, gitter, etc)
  Start from a base image like nvidia/cuda and install all the best goodies, including conda.