Update git submodules

* Update magnum from branch 'master'
  - Merge "[k8s_fedora_atomic] Delete floating ip for load balancer"
  - [k8s_fedora_atomic] Delete floating ip for load balancer
    
    When user creates LoadBalancer type service in k8s cluster, a floating
    ip may be created and associated with the load balancer VIP. Magnum
    now could delete the load balancers automatically in the cluster
    pre-delete method, should also remove the floating ip as needed.
    
    This patch depends on the github PR for cloud-provider-openstack:
    kubernetes/cloud-provider-openstack#433
    
    Story: 2004836
    Change-Id: Ia553aff4e66033346c6bfe120a72992bec79e136