1ffe0a10bd
When a more complex list of frames is to be rendered (like `1, 4, 5, 10,
15`), simplify the video filename to `{first}-{last}`.
Before: `somename-1, 4, 5, 10, 15.mp4`
Now: `somename-1-15.mp4`
These scripts are used for some (but far from all) unit tests.
It's mostly a place where we can add some extra files for the tests (like this
README.md and empty.js) that should be ignored by the job compiler, without
them getting embedded into the flamenco-manager executable file in production
builds.