Allow ramdisk_id, kernel_id to be null on schema
Allow ramdisk_id, kernel_id to be null on schema

Since is possible to create images with no
ramdisk_id, kernel_id parameters on glance v1,
then the schema-image.json needs to be modified to
allow null, string values for both attributes
and prevent LP #1447193 to happen with a glance v2
client.

Change-Id: I1319a1f6bdb69db90f9be7cf34df62cbd8538969
Closes-Bug: #1516330
Related-Bug: #1447193

mancdaz/openstack-ansible,major/openstack-ansible,git-harry/os-ansible-deployment,yanyao/newton,mrda/openstack-ansible,stackforge/os-ansible-deployment,jpmontez/openstack-ansible,bunchc/openstack-ansible,cfarquhar/openstack-ansible,open-switch/infra_openstack-ansible,yanyao/openstack-ansible,Logan2211/openstack-ansible,BjoernT/os-ansible-deployment,mrda/openstack-ansible,git-harry/os-ansible-deployment,jpmontez/os-ansible-deployment,major/openstack-ansible,weezer/openstack-ansible,jpmontez/openstack-ansible,bunchc/openstack-ansible,stackforge/os-ansible-deployment,jpmontez/os-ansible-deployment,weezer/openstack-ansible,BjoernT/openstack-ansible,open-switch/infra_openstack-ansible,open-switch/infra_openstack-ansible,Logan2211/openstack-ansible,yanyao/openstack-deployment-liberty,yanyao/newton,major/os-ansible-deployment,jpmontez/os-ansible-deployment,yanyao/openstack-deployment-liberty,cfarquhar/openstack-ansible,major/os-ansible-deployment,os-cloud/os-ansible-deployment,yanyao/openstack-deployment-liberty,robb-romans/openstack-ansible,cloudnull/os-ansible-deployment,BjoernT/os-ansible-deployment,mancdaz/openstack-ansible,cloudnull/os-ansible-deployment,BjoernT/openstack-ansible,jpmontez/openstack-ansible,openstack/openstack-ansible,os-cloud/os-ansible-deployment,openstack/openstack-ansible,yanyao/openstack-ansible,mrda/openstack-ansible,robb-romans/openstack-ansible,git-harry/os-ansible-deployment,BjoernT/os-ansible-deployment