Version bump

Dirk Hoekstra · Dirk Hoekstra · commit 902e16d2261c · 2017-10-25T16:00:36.000+02:00
diff --git a/client.go b/client.go
@@ -22,7 +22,7 @@ import (
 
 const (
 	// ClientVersion is used in User-Agent request header to provide server with API level.
-	ClientVersion = "3.0.0"
+	ClientVersion = "4.0.0"
 
 	// Endpoint points you to MessageBird REST API.
 	Endpoint = "https://rest.messagebird.com"
