Use 1.1.10 as hot base image and test borg binary by outputting the version number.
This MR pushes the base images to version 1.1.10 to make future builds even faster.
I tried for too long to get the tox tests to run properly and in decent time to not hit some timeout but nothing worked. So for now just output the borg binary version with borg --version to make sure the binary was built correctly.
There should be no problems with these builds. If users start reporting issues, we'll take a closer look.