Change the README badges and their placement.

[teo-tsirpanis]

GitLab CI and CircleCI are not maintained (the first at least is not visible).

AppVeyor's badge image link needs to be updated.

[matthid]

Probably fair, while gitlab is still in use it is not publically visible for some reason (I just looked at it: There doesn't seem to be any setting for it. I always have to log in to see the build). CirlcleCI indeed stopped working and I never cared to much to enable it again I guess :)

[teo-tsirpanis]

You have to update the link for AppVeyor's badge image; it still points to the old one, where the build is successful. Because it seemed to be private, I couldn't do it myself.

[matthid]

@teo-tsirpanis Can you repeat what exactly is still missing with the AppVeyor badge? Currently it seems to be OK:

[teo-tsirpanis]

It is the badge's picture. It always says "BUILD PASSING" even when it was failing in the past, because it still using the old project.

You have to get the new URL from AppVeyor's settings:

[matthid]

@teo-tsirpanis Thanks for the fast response. I think I got it sorted out...