Fixes #20: add an extra file for CouchDB to put uuid into

CouchDB will put the `uuid` into the 'last file in the configuration
chain' (see: https://issues.apache.org/jira/browse/COUCHDB-2064). Added
a file that will be last lexicographically (with name in upper case), so
the file managed by Chef won't be touched on every restart.
OK, so your setup is the same as what I want to achieve here, with only exception of calling the file `${INSTANCE}.ini` instead of `UDID.ini`. I'm totally fine with this. From what I understand, we would add `default['couch_db']['instance_name'] = node['hostname']` to `attributes/default.rb`?