Add relicense agreement from Brian Adamson

RELICENSE/bebopagogo.md

+# Permission to Relicense under MPLv2
+
+This is a statement by Brian Adamson that grants permission to relicense its
+copyrights in the libzmq C++ library (ZeroMQ) under the Mozilla Public License v2
+(MPLv2).
+
+A portion of the commits made by the Github handle "bebopagogo", with commit
+author "bebopagogo <bebopagogo@users.noreply.github.com>" and "Brian Adamson
+<badamson@gmail.com>", are copyright of Brian Adamson. This document hereby grants
+the libzmq project team to relicense libzmq, including all past, present and
+future contributions of the author listed above.
+
+Brian Adamson 2019/08/11 s