* Update all Jest packages to 17.x, cache babel-jest transforms
* Remove the caching
Looking at the other builds it doesn't seem to actually be that necessary. The bottleneck is executors, not build time.
* Remove unnecessary package, fix fiber test runner
* Regenerate yarn lockfile
I'll plan to change all of our console.error and component-tree expects to expectDev. It's a little annoying that we need to make sure tests don't throw (see my change to normalizeCodeLocInfo) but any alternative would seem to require two separate test runs or a much more cumbersome syntax.