httplib support to set the protocol version for incoming requests

@@ -73,3 +73,8 @@ httplib support mutil file upload, use `b.PostFile()`
 		t.Fatal(err)
 		t.Fatal(err)
 	}
 	}
 	fmt.Println(str)
 	fmt.Println(str)
+
+## set HTTP version
+some servers need to specify the protocol version of HTTP
+
+	httplib.Get("http://beego.me/").SetProtocolVersion("HTTP/1.1")
\ No newline at end of file

@@ -109,6 +109,23 @@ func (b *BeegoHttpRequest) Header(key, value string) *BeegoHttpRequest {
 	return b
 	return b
 }
 }
 
 
+// Set the protocol version for incoming requests.
+// Client requests always use HTTP/1.1.
+func (b *BeegoHttpRequest) SetProtocolVersion(vers string) *BeegoHttpRequest {
+	if len(vers) == 0 {
+		vers = "HTTP/1.1"
+	}
+
+	major, minor, ok := http.ParseHTTPVersion(vers)
+	if ok {
+		b.req.Proto = vers
+		b.req.ProtoMajor = major
+		b.req.ProtoMinor = minor
+	}
+
+	return b
+}
+
 // SetCookie add cookie into request.
 // SetCookie add cookie into request.
 func (b *BeegoHttpRequest) SetCookie(cookie *http.Cookie) *BeegoHttpRequest {
 func (b *BeegoHttpRequest) SetCookie(cookie *http.Cookie) *BeegoHttpRequest {
 	b.req.Header.Add("Cookie", cookie.String())
 	b.req.Header.Add("Cookie", cookie.String())