Update net-attach-def client library to 1.7.5 for cri-o functionality

[dougbtv]

From the release notes:

This release contains a fix related to the determination of the default interface, e.g. setting the default parameter to true in the network-status annotation based on the presence of a gateway in the CNI ADD success result ips.gateway and makes the determination of the default based on the first interface that has an associated value of gateway (using the interface index in the ips element in the CNI ADD success result).

This provides flexibility especially in CRI-O which uses the first interface and IP addresses for the pod.IP in Kubernetes, therefore. Containerd functionality is unchanged in that it uses the value for the IP addresses specifically

It's worth noting that CNI ADD success results which do not contain any interfaces will be discarded in this determination of the default, therefore it's recommended to set one with an associated gateway if aiming to have it be noted as the default.

See also:
https://github.com/k8snetworkplumbingwg/network-attachment-definition-client/releases/tag/v1.7.5 k8snetworkplumbingwg/network-attachment-definition-client#73

[coveralls]

coverage: 63.857%. remained the same
when pulling ecf5854 on dougbtv:net-attach-def-lib-175
into adfb270 on k8snetworkplumbingwg:master.