Cleanup: remove dead code and improve layout

This is a cleanup PR addressing several issues:

o Removes the variant simulator (issue #27)
o Improves CLI code layout and removes the need for irritating symlinks when developing (issue #24)

Also updates the README to more accurately reflect the current state of the project.
We were only using the future package in the client module to make `http.client` work on both 2.7 and 3.x. Since we've moved over to using requests this isn't necessary, and I got rid of the dependency. If we need `future` for something in the future though, I'm completely happy to bring it back --- it just seems a bit confusing to have a dependency on something that we're not actually using.