Prepare v5.2 release

[schweikert]

No description provided.

[coveralls]

coverage: 84.768%. remained the same
when pulling 9f64904 on push-ukoxnvwnypvv
into bd44c9f on develop.

[schweikert]

@auerswal @gsnw I am preparing a new release. Let me know if you have any concerns / additions before I do it.

Btw. I also send an invite to add you both as collaborators on the repository, so that if you want you can also triage bugs, merge pull requests, etc.

[gsnw]

From my point of view there is nothing to be said against the creation of version 5.2

[auerswal]

I support making a release with the current set of fixes and additions. :-)