Changing back the version of Rmath seems unintended.

This can happen inadvertently when you rebase/merge or switch branches between branches where others have updated the submodule in between, and do not run `git submodule update` before committing. For this reason our `make` script calls `git submodule update` about 14 times in a build, but if you commit without running make first, you will get problems like this. This is in my opinion the most annoying/stupid design decision in `git`, but fortunately solving problems like this will teach you more about using git for more complex tasks and with more confidence.

To reset this, you have to `cd deps/Rmath && git checkout e61abe6` and then commit again. You will also have to revert 02972ecd1. If you would also rebase and squash all your commits into a single commit, we will also have a much shorter and easier history to work with. I (and probably a few others here), can help you with this process, or I can just fix it on my system and submit a new PR with one correct commit and you as the author.