implemented create team <-> namespace relation

models/team_namespace_rights.go

@@ -0,0 +1,7 @@
+package models
+
+// CanCreate checks if one can create a new team <-> namespace relation
+func (tn *TeamNamespace) CanCreate(user *User, _ int64) bool {
+	n, _ := GetNamespaceByID(tn.NamespaceID)
+	return n.IsAdmin(user)
+}