Sync devDependencies and npm scripts

[joshjohanning]

Probably 2 separate options. But want to sync devDependencies from a sample package.json file as well as a separate option for syncing npm run commands from a package.json.

The devDependencies are tricky bc after updating package.json you need to run npm install to update the package-lock.json too and commit that file also. In the same commit in the API would be nice!