Remove pyup and fix typo in a docstring

[dethos]

Removes a service that no longer is being used and an alternative is already provided by GitHub.

closes #316

[dethos]

Looks good. Should we also add the config file for dependabot?

@lopesrb Any suggestion for configs not included by default?

[lopesrb]

@dethos I don't know the defaults but probably update_schedule and default_reviewers feel free to ignore if you find that's not necessary

[dethos]

@lopesrb It took a while :), but here it is. Can you review again?

[lopesrb]

@dethos looks good :)

[dethos]

Thanks. Well it seems I still can't merge, this repository settings must be messed up. Ping @pjaneiro .