Snapshooter tests fail under MacOs

[mtsfoni]

There is currently no known work-around.

See here: SwissLife-OSS/snapshooter#196

It may be an option to just build this Snapshot functionality by ourselves to reduce dependencies on libraries and have more control about what's happening.

[mtsfoni]

Snapshooter was incorrectly searching for snapshots under // on all operating systems. This was resolved on Linux and Windows by creating a symlink to // or [Drive]:/_/. However, macOS does not permit this symlink, so I have decided to skip tests on macOS for now and prioritize other issues.

a27d923

Leaving this open, in case anyone wants to try to find a fix for macOS.