set grpc by default (#1070)

defaults.go

@@ -0,0 +1,17 @@
+package micro
+
+import (
+	"github.com/micro/go-micro/client"
+	"github.com/micro/go-micro/server"
+
+	// set defaults
+	gcli "github.com/micro/go-micro/client/grpc"
+	gsrv "github.com/micro/go-micro/server/grpc"
+)
+
+func init() {
+	// default client
+	client.DefaultClient = gcli.NewClient()
+	// default server
+	server.DefaultServer = gsrv.NewServer()
+}