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.
I don't want to nag, but now that `install()` is in fact the only method that can be called on a `ModuleInstaller` object  and calling this method twice is useless, I see no sense in making this a class at all. It would be easier to use if this was just a module with one public function `install(module_name)` IMHO.