xci: Bump Kubespray SHA and sync Ansible versions

xci: Bump Kubespray SHA and sync Ansible versions

This change
- bumps kubespray version to 8b3ce6e418ccf48171eb5b3888ee1af84f8d71ba, taking
Kubernetes version from 1.10.2 to 1.10.4.
- pins Ansible version used by Kubespray to same Ansible version as the rest.
The var kept as is in case if we need to pin Kubespray to a different Ansible
version in future.

installer-type:kubespray
deploy-scenario:k8-calico-nofeature

Change-Id: Iefbe82f0b9b10296e4362bca07630047c56630ac
Signed-off-by: Fatih Degirmenci <fdegir@gmail.com>