Add create user rest endpoint
diff --git a/core/kg/common/interfaces.go b/core/kg/common/interfaces.go
index daee20e..2c20e28 100644
--- a/core/kg/common/interfaces.go
+++ b/core/kg/common/interfaces.go
@@ -14,4 +14,5 @@
 
 type AppIface interface {
 	GetUser(userID string) (*model.User, error)
+	CreateUser(user *model.User) (*model.User, error)
 }