Modules installer

This is a simple modules installer (can't handle multiple files, or requirements yet)

It connects to http://jaspermoduleshub.herokuapp.com/

I added a `walk_packages` on `brain.py` so that modules can be installed in subfolders.
The idea is to maintain a similar level of abstraction inside the `install` function. Therefore, that module calls the function that depict the inner working. You'll sometimes end up with functions that wrap only one statement, but it's a price you pay for the simplicity of the final code. Anyway, I don't think inlining this statement would entail any benefits, other than having one function less in the module.