Update date reference in the package.

todonotes.dtx

@@ -22,14 +22,14 @@
 %<package>\NeedsTeXFormat{LaTeX2e}[1999/12/01]
 %<package>\ProvidesPackage{todonotes}
 %<*package>
-    [2015/07/09 .dtx Todonotes source and documentation.]
+    [2018/09/08 .dtx Todonotes source and documentation.]
 %</package>
 %
 %<*driver>
 \documentclass{ltxdoc}
 \usepackage{wrapfig}
 \usepackage[colorlinks, linkcolor=black, urlcolor=blue]{hyperref}
-\usepackage[colorinlistoftodos, shadow]{todonotes}[2015/07/09]
+\usepackage[colorinlistoftodos, shadow]{todonotes}[2018/09/08]
 \usepackage{amsmath}
 \usepackage{setspace}
 \usepackage{soul}