Allow digits in subversion username when generating authors list from…

… svn log.

README.markdown

@@ -153,7 +153,7 @@ repository which name on its own line. This would allow you to easily
 redirect the output of this command sequence to ~/.svn2git/authors and have
 a very good starting point for your mapping.
 
-    $ svn log | grep -E "r[0-9]+ \| [a-z]+ \|" | awk '{print $3}' | sort | uniq
+    $ svn log | grep -E "r[0-9]+ \| [a-z0-9]+ \|" | awk '{print $3}' | sort | uniq
 
 Debugging
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