Multiple small fixes for the vagrant environment
    
    - Drop the hardcoded pagure config in ~ since we actually use the
      one in /etc/pagure.
    
    - Install the new dependency whitenoise that handles the static files
      cf https://pagure.io/pagure/pull-request/4885
    
    - Create the /usr/local/lib/python... folder before trying to create
      a symlinkg in it
    
    - Fix the symlink created in /usr/local/lib/python... so it points
      to the pagure module rather than the git clone (ie one level to
      high)
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>