feat(client): add SetDialTimeout method
feat(client): add SetDialTimeout method

Enables this to be customized from the default of 1 second.

barakmich/go-etcd,giantswarm/go-etcd,pquerna/go-etcd,pengzj/go-etcd,coreos/go-etcd,nordligulv/go-etcd,mischief/go-etcd,kmchen/go-etcd,shafreeck/go-etcd,wangyumi/go-etcd,Yhgenomics/go-etcd,mbrukman/go-etcd,stormltf/go-etcd