Add wrapper implementation

client/wrapper.go

@@ -0,0 +1,37 @@
+/*
+Wrapper is a type of middleware for the go-micro client. It allows
+the client to be "wrapped" so that requests and responses can be intercepted
+to perform extra requirements such as auth, tracing, monitoring, logging, etc.
+
+Example usage:
+
+	import (
+		"log"
+		"github.com/micro/go-micro/client"
+
+	)
+
+	type LogWrapper struct {
+		client.Client
+	}
+
+	func (l *LogWrapper) Call(ctx context.Context, req Request, rsp interface{}) error {
+		log.Println("Making request to service " + req.Service() + " method " + req.Method())
+		return w.Client.Call(ctx, req, rsp)
+	}
+
+	func Wrapper(c client.Client) client.Client {
+		return &LogWrapper{c}
+	}
+
+	func main() {
+		c := client.NewClient(client.Wrap(Wrapper))
+
+	}
+
+
+*/
+package client
+
+// Wrapper wraps a client and returns a client
+type Wrapper func(Client) Client