Update dates in LICENSE

LICENSE

@@ -2,8 +2,8 @@ MIT/X Consortium License
 
 © 2009-2012 Aurélien APTEL <aurelien dot aptel at gmail dot com>
 © 2009 Anselm R Garbe <garbeam at gmail dot com>
-© 2012-2014 Roberto E. Vargas Caballero <k0ga at shike2 dot com>
-© 2012-2014 Christoph Lohmann <20h at r-36 dot net>
+© 2012-2015 Roberto E. Vargas Caballero <k0ga at shike2 dot com>
+© 2012-2015 Christoph Lohmann <20h at r-36 dot net>
 © 2013 Eon S. Jeon <esjeon at hyunmu dot am>
 © 2013 Alexander Sedov <alex0player at gmail dot com>
 © 2013 Mark Edgar <medgar123 at gmail dot com>