Update federation target to etcd/clientv3 (#6119)

With CoreDNS now supporting etcdv3 as the DNS backend, we
can update our federation target to etcdv3. Users will now be
able to use etcdv3 server as the federation backbone.

Minio will update bucket data to etcdv3 and CoreDNS can pick
that data up and serve it as bucket style DNS path.

vendor/google.golang.org/grpc/Makefile

@@ -1,4 +1,4 @@
-all: test testrace
+all: vet test testrace
 
 deps:
 	go get -d -v google.golang.org/grpc/...
@@ -20,24 +20,20 @@ proto:
 		echo "error: protoc not installed" >&2; \
 		exit 1; \
 	fi
-	go get -u -v github.com/golang/protobuf/protoc-gen-go
-	# use $$dir as the root for all proto files in the same directory
-	for dir in $$(git ls-files '*.proto' | xargs -n1 dirname | uniq); do \
-		protoc -I $$dir --go_out=plugins=grpc:$$dir $$dir/*.proto; \
-	done
+	go generate google.golang.org/grpc/...
+
+vet:
+	./vet.sh
 
 test: testdeps
-	go test -v -cpu 1,4 google.golang.org/grpc/...
+	go test -cpu 1,4 -timeout 5m google.golang.org/grpc/...
 
 testrace: testdeps
-	go test -v -race -cpu 1,4 google.golang.org/grpc/...
+	go test -race -cpu 1,4 -timeout 7m google.golang.org/grpc/...
 
 clean:
 	go clean -i google.golang.org/grpc/...
 
-coverage: testdeps
-	./coverage.sh --coveralls
-
 .PHONY: \
 	all \
 	deps \
@@ -46,7 +42,7 @@ coverage: testdeps
 	updatetestdeps \
 	build \
 	proto \
+	vet \
 	test \
 	testrace \
-	clean \
-	coverage
+	clean