baremetal: Create clouds.yaml file on bootstrap

If it becomes necessary to connect to the ironic or inspector services
from the command line for debugging purposes, it is useful to have a
clouds.yaml file available for the openstack client to use. Generate
this file in the correct format on the bootstrap host for convenience.

data/data/bootstrap/baremetal/files/opt/metal3/auth/clouds.yaml.template

@@ -0,0 +1,7 @@
+clouds:
+  metal3-bootstrap:
+    auth_type: http_basic
+    username: {{.PlatformData.BareMetal.IronicUsername}}
+    password: {{.PlatformData.BareMetal.IronicPassword}}
+    baremetal_endpoint_override: http://{{.PlatformData.BareMetal.ProvisioningIP}}:6385/v1
+    baremetal_introspection_endpoint_override: http://{{.PlatformData.BareMetal.ProvisioningIP}}:5050/v1