Update protobuf,grpc,etcd dependencies

1. Updated etcd/protobuf/grpc dependencies:

echo "
hack/pin-dependency.sh github.com/golang/protobuf latest
hack/pin-dependency.sh google.golang.org/protobuf latest
hack/pin-dependency.sh go.etcd.io/etcd/api/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/client/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/client/pkg/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/pkg/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/server/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/tests/v3 v3.5.0-rc.0
hack/pin-dependency.sh google.golang.org/grpc latest
" | bash

2. Linted transitive dependencies until versions are clean:

hack/lint-dependencies.sh  | grep "  hack/pin-dependency.sh" | bash

3. Linted dependencies until dropped versions are clean:

hack/lint-dependencies.sh  | grep "dropreplace" | bash

4. Updated vendor and internal modules:

hack/update-vendor.sh
hack/update-internal-modules.sh

Repeated steps 2-4 until clean

vendor/github.com/grpc-ecosystem/go-grpc-middleware/go.mod

@@ -0,0 +1,22 @@
+module github.com/grpc-ecosystem/go-grpc-middleware
+
+require (
+	github.com/go-kit/kit v0.9.0
+	github.com/go-logfmt/logfmt v0.4.0 // indirect
+	github.com/go-stack/stack v1.8.0 // indirect
+	github.com/gogo/protobuf v1.3.2
+	github.com/golang/protobuf v1.3.3
+	github.com/opentracing/opentracing-go v1.1.0
+	github.com/pkg/errors v0.8.1 // indirect
+	github.com/sirupsen/logrus v1.4.2
+	github.com/stretchr/testify v1.4.0
+	go.uber.org/atomic v1.4.0 // indirect
+	go.uber.org/multierr v1.1.0 // indirect
+	go.uber.org/zap v1.10.0
+	golang.org/x/net v0.0.0-20201021035429-f5854403a974
+	golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be
+	google.golang.org/genproto v0.0.0-20200423170343-7949de9c1215 // indirect
+	google.golang.org/grpc v1.29.1
+)
+
+go 1.14