Update project to use devtools

This branch should update the project to use devtools. The diff with master should be kept as small as possible, and simple mutations should be fixed and then cherry-picked into master.

Once all the mutations are fixed, then this should be rebased against master and merged. It should be roughly similar to: https://github.com/dkubb/veritas/commit/343a0cbd54da82158ccdbdc033865b743e8e7c44