The salt-cloud packages automatically pull in the pycrypto and libcloud
dependencies for RedHat and Debian (at least when using the SaltStack
repos), so it doesn't really make sense to install these dependencies
using pip. By default we no longer use pip, but the old behaviour can be
restored by setting 'salt:use_pip' to True in the pillar.
There could probably be a case made for removing the pip stuff
altogether, but we will leave it in for the time being to preserve some
backwards compatibility.