Remove AGPL license statements

This project had become MIT.

Author: Seulgi Kim

src/lib.rs

@@ -1,19 +1,3 @@
-// Copyright 2018 Kodebox, Inc.
-// This file is part of CodeChain.
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
 use std::ops::{Drop, FnOnce};
 
 pub struct Finally<F>