fix whitespace

I know mentioned you were going to configure this later, but in case it's useful, here's a basic Python indentation settings set for vim:
    set tabstop=8
    set expandtab
    set softtabstop=4
    set shiftwidth=4

I'm getting this from [my settings] (https://github.com/thomasballinger/vim), more specifically [here](https://github.com/thomasballinger/vim/blob/master/ftplugin/python_custom.vim)