Correct licence on closed contour module

AUTHORS.md

@@ -4,6 +4,7 @@ The following people have contributed to the project (in alphabetical order):
 
 - [Martin Bentley](https://github.com/mtb-za), Agile Scientific, Canada
 - [Evan Bianco](https://github.com/EvanBianco), Agile Scientific, Canada
-- [Matt Hall](https://github.com/kwinkunks), Agile Scientific, Canada (ORCID: [0000-0002-4054-8295](https://orcid.org/0000-0002-4054-8295))
+- [Rob Gooder](https://github.com/ragooder/), United Kingdom
+- [Matt Hall](https://github.com/kwinkunks), Equinor, Norway (ORCID: [0000-0002-4054-8295](https://orcid.org/0000-0002-4054-8295))
 - [Matteo Niccoli](https://github.com/mycarta), Canada
 - [Steve Purves](https://github.com/stevejpurves), Spain

gio/closure.py

@@ -1,8 +1,28 @@
 """
 Closed-contour-related functions.
 
-Author: Matt Hall, Rob Gooder
-License: Apache 2.0
+Author: Rob Gooder, Matt Hall
+License: MIT License
+
+Copyright (c) 2023 Rob Gooder, Matt Hall
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
 """
 from typing import List