Custom Anaconda installers

[agitter]

The conda constructor project could be a perfect solution for our installation challenges. From the readme:

Constructor is a tool which allows constructing an installer for a collection of conda packages. It solves needed packages using user-provided specifications, and bundles those packages. It can currently create 3 kinds of installers, which are best thought of as delivery vehicles for the bundled packages. There are shell installers, MacOS .pkg installers, and Windows .exe installers. Each of these will create an environment on the end user's system that contains the specs you provided, along with any necessary dependencies. These installers are similar to the Anaconda and Miniconda installers, and indeed constructor is used to create those installers.

It would be great to test this with our environment.

This would address https://github.com/gitter-lab/ml4bio/issues/20