Changes explanation:
slave_reference.lower(): The configparser which the current buildout
using is case sensitive, which cause some options cannot be found.
slap_software_type: The recipe softwaretype need this option, but
switch-softwaretype doesn't.
caddyprofiledeps: It provides the deps of caddy. Switch to
switch-softwaretype leads to the error like "ImportError: No module
named furl". Force caddyprofiledeps installed first can solve this
issue.