vendor: bump etcd deps

As per https://github.com/etcd-io/etcd/blob/fa57f7fbc787b4/Gopkg.lock

List of packages required by subset of etcd used is provided by:

go list -f '{{join .Deps "\n"}}' \
 github.com/docker/docker/vendor/github.com/coreos/etcd/... \
 | grep -F . | grep -v coreos/etcd | sort | uniq

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

vendor.conf

@@ -135,16 +135,16 @@ golang.org/x/time fbb02b2291d28baffd63558aa44b4b56f178d650
 github.com/hashicorp/go-memdb cb9a474f84cc5e41b273b20c6927680b2a8776ad
 github.com/hashicorp/go-immutable-radix 826af9ccf0feeee615d546d69b11f8e98da8c8f1 git://github.com/tonistiigi/go-immutable-radix.git
 github.com/hashicorp/golang-lru 0fb14efe8c47ae851c0034ed7a448854d3d34cf3
-github.com/coreos/pkg fa29b1d70f0beaddd4c7021607cc3c3be8ce94b8
+github.com/coreos/pkg v3
 github.com/pivotal-golang/clock 3fd3c1944c59d9742e1cd333672181cd1a6f9fa0
-github.com/prometheus/client_golang 52437c81da6b127a9925d17eb3a382a2e5fd395e
-github.com/beorn7/perks 4c0e84591b9aa9e6dcfdf3e020114cd81f89d5f9
-github.com/prometheus/client_model fa8ad6fec33561be4280a8f0514318c79d7f6cb6
-github.com/prometheus/common ebdfc6da46522d58825777cf1f90490a5b1ef1d8
-github.com/prometheus/procfs abf152e5f3e97f2fafac028d2cc06c1feb87ffa5
+github.com/prometheus/client_golang v0.8.0
+github.com/beorn7/perks 3a771d992973f24aa725d07868b467d1ddfceaf
+github.com/prometheus/client_model 6f3806018612930941127f2a7c6c453ba2c527d2
+github.com/prometheus/common 7600349dcfe1abd18d72d3a1770870d9800a7801
+github.com/prometheus/procfs 7d6f385de8bea29190f15ba9931442a0eaef9af7
 github.com/matttproud/golang_protobuf_extensions v1.0.0
 github.com/pkg/errors 839d9e913e063e28dfd0e6c7b7512793e0a48be9
-github.com/grpc-ecosystem/go-grpc-prometheus 6b7015e65d366bf3f19b2b2a000a831940f0f7e0
+github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0
 
 # cli
 github.com/spf13/cobra v0.0.3