Deal with lock file changes polluting commits

Every time we `npm install` it updates `package-lock.json` and `npm-shrinkwrap.json` files throughout the tree. This is annoying, and people not familiar with how these files work will often mess it up, rebases and merges get tricky due to merge conflicts, etc.

Let's see if we can improve this. We could try [disabling them](https://github.com/substack/tape/commit/df48bfae19d8ba4b48055dacac8b81912b8887f2). Since we do `npm install` in various places, we'll need to figure out how to pass that down, or have it get read from our root dir.