[#11] Build simple neofs-node application

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

cmd/neofs-node/main.go

@@ -1,10 +1,22 @@
 package main
 
 import (
+	"log"
+
 	"github.com/nspcc-dev/neofs-node/pkg/util/grace"
 )
 
+func fatalOnErr(err error) {
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
 func main() {
+	c := defaultCfg()
+
+	fatalOnErr(serveGRPC(c))
+
 	ctx := grace.NewGracefulContext(nil)
 
 	<-ctx.Done()