Close stream when reading/writing is done.

src/main/org/insa/graph/io/BinaryPathReader.java

             nodes.add(readNode(graph));
         }
 
+        this.dis.close();
+
         return Path.createFastestPathFromNodes(graph, nodes);
     }
 

src/main/org/insa/graph/io/BinaryPathWriter.java

         }
 
         dos.flush();
+        dos.close();
     }
 
 }