Add copyright for the Python bindings.

doc/LICENSE

@@ -19,6 +19,22 @@ Sudo is distributed under the following license:
    Agency (DARPA) and Air Force Research Laboratory, Air Force
    Materiel Command, USAF, under agreement number F39502-99-1-0512.
 
+The Python plugin bindings bear the following license:
+
+   Copyright (c) 2019 Robert Manner <robert.manner@oneidentity.com>
+
+   Permission to use, copy, modify, and distribute this software for any
+   purpose with or without fee is hereby granted, provided that the above
+   copyright notice and this permission notice appear in all copies.
+
+   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+   ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
 The file redblack.c bears the following license:
 
    Copyright (c) 2001 Emin Martinian