automaton.hh: fix the vertex property for the CSR graph

Using the void old syntax does not work anymore since Boost 1.55.
Use boost:no_property instead.

include/rukia/automaton.hh

@@ -1,20 +1,20 @@
-// Copyright (C) Univ. Paris-SUD, Johan Oudinet <[email protected]> - 2008, 2009, 2010
-//  
+// Copyright (C) Univ. Paris-SUD, Johan Oudinet <[email protected]> - 2008, 2009, 2010, 2018
+//
 // This file is part of Rukia.
-//  
+//
 // Rukia is free software: you can redistribute it and/or modify it
 // under the terms of the GNU Lesser General Public License as
 // published by the Free Software Foundation, either version 3 of the
 // License, or (at your option) any later version.
-//  
+//
 // Rukia 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
 // Lesser General Public License for more details.
-//  
+//
 // You should have received a copy of the GNU Lesser General Public
 // License along with Rukia.  If not, see <http://www.gnu.org/licenses/>.
-//  
+//
 #ifndef RUKIA_AUTOMATON_HH
 # define RUKIA_AUTOMATON_HH
 # include <string>
@@ -43,7 +43,7 @@ namespace rukia {
 
   typedef boost::compressed_sparse_row_graph<
     boost::directedS,
-    void,
+    boost::no_property,
     detail::transition>		automaton;
 
 } // end namespace rukia