[QGIS-Developer] Cleanup of Docker images on qgis2

[Richard Duivenvoorde]

Hi,

We run several docker containers on qgis2:
- building of websites
- building of documentation
- plugins Django app
- demo.qgis.org

Those all run in Debian containers...

BUT there are a lot of other images flying around there, from earlier
experiments or ....:
- centos
- like 5 versions of ubuntu
- phusion ?
- <none. / unnamed ones

The plan is to clean up a little in those.
So can everybody who has an image of value there raise a hand?
Else I'll purge all images not needed (size ranging from 0.5 to 10 Gb),
to regain some diskspace/inodes.

Regards,

Richard Duivenvoorde