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.
can you make `install_dependencies` default to `False` and `install_location` default to `jasperpath.PLUGIN_PATH`? Even better would be if you'd add `jasperpath.config('plugins')` to `get_modules` in `brain.py` and then used `jasperpath.config('plugins')` as default here.