docs(cluster-size): remove outdated refrences to flag max-cluster-size
flags: alias max-cluster-size to cluster-active-size as deprecated flag
flags: remove MaxClusterSize variable
Merge pull request #849 from colegleason/max-cluster-size

docs(cluster-size): remove outdated references to flag max-cluster-size
all: deprecate v1 support

Etcd moves to 0.5 without the support of v1.
server: return 404 for v1 http endpoint

instead of 403