`FIXED_NETWORK_CIDR` environment variable is mandatory by
openstack-heat kubernetes provider, but it's missing as
default value. Adding this environment variable is helpful
to build kubernetes cluster using openstack-heat provider.
So this patch adds it.
Fixed the order of fields for basic_auth.
This provider still needs to leverage common.sh for generating proper credentials though.
Also documented a pattern for how to get the SWIFT_SERVER_URL automatically
