README.md: Add section about Licensing

Signed-off-by: Alan Orth <alan.orth@gmail.com>

README.md

@@ -50,3 +50,19 @@ And finally, bring the machine up:
 ```console
 vagrant up
 ```
+
+### License
+Copyright (C) 2014 - 2015 Alan Orth
+
+The contents of this repository are 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/>.