Update version information for libzip and zlib (#249)

* Update version information for libzip and zlib

* Revert ZLIB Readme file

README.md

@@ -40,8 +40,8 @@ This page also contains a section about building lib3mf from source or obtaining
 
 ## Licenses and third party code
 lib3mf is released under the [BSD license](LICENSE). The library contains code of the following [third parties](SDK/Credits.txt):
-1. libzip 1.2.8, https://libzip.org/license/
-2. zlib 1.2.8, http://www.zlib.net/zlib_license.html
+1. libzip 1.2.11, https://libzip.org/license/
+2. zlib 1.7.3, http://www.zlib.net/zlib_license.html
 3. cpp-base64 1.01.00, https://github.com/ReneNyffenegger/cpp-base64/blob/master/LICENSE
 
 In addition, the automated tests of lib3mf make use of LibReSSL 3.0.2, [License](Tests/libressl/COPYING).

SDK/Credits.txt

@@ -7,21 +7,23 @@ libzip 1.7.3
 https://libzip.org/license/
 Copyright (C) 1999-2020 Dieter Baron and Thomas Klausner
 
-This file is part of libzip, a library to manipulate ZIP archives.
 The authors can be contacted at <[email protected]>
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
+
 1. Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
+  notice, this list of conditions and the following disclaimer.
+
 2. Redistributions in binary form must reproduce the above copyright
- notice, this list of conditions and the following disclaimer in
- the documentation and/or other materials provided with the
- distribution.
+  notice, this list of conditions and the following disclaimer in
+  the documentation and/or other materials provided with the
+  distribution.
+
 3. The names of the authors may not be used to endorse or promote
- products derived from this software without specific prior
- written permission.
+  products derived from this software without specific prior
+  written permission.
 
 THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED