src/sage/modules/vector_double_dense.pyx: Update copyright according …

…to 'git blame -w --date=format:%Y src/sage/modules/vector_double_dense.pyx | sort -k2'

src/sage/modules/vector_double_dense.pyx

@@ -32,13 +32,20 @@ AUTHORS:
 """
 
 #*****************************************************************************
-#       Copyright (C) 2006 William Stein <wstein@gmail.com>
+#       Copyright (C) 2006-2010 William Stein <wstein@gmail.com>
+#       Copyright (C) 2009      Alexandru Ghitza
+#       Copyright (C) 2020      Antonio Rojas
+#       Copyright (C) 2017      Frédéric Chapoton
+#       Copyright (C) 2008-2009 Jason Grout
+#       Copyright (C) 2014-2016 Jeroen Demeyer
+#       Copyright (C) 2011      Mike Hansen
+#       Copyright (C) 2011      Rob Beezer
 #
 # 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 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
+#                  https://www.gnu.org/licenses/
 #*****************************************************************************
 
 cimport numpy