--- features: - The adds support for pxc to grow a cluster. * api and taskmanager support for shrinking a cluster * validate that the networks given are the same for each instance in the cluster. * make sure to add the existing networks on an instance in the cluster. * add new Error task for grow and shrink. * nova client version configuration changed to a string option rather than an int option because the nova microversions change nova api output. This was needed for the network interfaces on existing instances. * testing for grow and shrink cluster