Bot that automatically commit submodules

[illwieckz]

One problem with submodules is that we forget to update submodule references in parent repository, meaning that when someone bisects a parent repository, there state of submodules can't be trusted.

So I have an idea of a simple bot that:

• clones recursively Unvanquished
• pulls master on every repository and submodules (using git-checkout-modules)
• commits submodule changes

and probably do the same with branches like 0.53.0/sync.

The idea is that the bot runs once a day.