minor amendments to release process/changelog

based on lessons learned from failed release v0.39.0,
`git push && git push --follow-tags` is smarter because
it reduces the chance of an unreleasable tag being pushed.
(git pushes the tags before it pushes the commits).

developer/bin/generate_changelog

@@ -245,7 +245,7 @@ end
 
 def footer
   @footer ||= Set.new
-  @footer.to_a
+  @footer.to_a.sort
 end
 
 def add_to_footer(line)