Support for detecting and installing changes from Gemfiles

[nottrobin]

No description provided.

[nottrobin]

It seems to be impossible to get Ruby working properly within a strictly confined snap - the official Ruby snap also isn't strictly confined.

Probably the only way to add Ruby support is to make the confinement of this snap classic, similarly to how it works for the Ruby snap itself. This could also help us out with our other confinement issues, but unfortunately classic snaps need approval, and when I tried to get dotrun working with classic confinement it was a challenge.

[nottrobin]

We're giving up on this - instead of supporting Ruby, we're going to move all our static sites from Jekyll to Eleventy, so we don't need Ruby support.