Add license LGPLv3

README.md

 # queue-thread-safe
 
 A thread-safe asynchronous queue in C++11 inspired in glib asynchronous queue (https://developer.gnome.org/glib/2.50/glib-Asynchronous-Queues.html)
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+
+
+## License
+
+The LGPL License (LGPL-3+)
+
+Copyright (c) 2019 Alfredo Pons - apons@linucleus.com
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.