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* Added
- Ability to specify robots.txt file for ``sitemap_to_df``
- Ability to retreive any kind of sitemap (news, video, or images)
- Errors column to the returnd DataFrame if any errors occur
- A new ``sitemap_downloaded`` column showing datetime of getting the
sitemap
* Fixed
- Logging issue causing ``sitemap_to_df`` to log the same action twice
- Issue preventing URLs not ending with xml or gz from being retreived
- Correct sitemap URL showing in the ``sitemap`` column