Bug Report or Feature Request (mark with an x)

- [ ] bug report -> please search issues before submitting
- [x] feature request

Desired functionality.

After updated the CLI version, sometimes package.json is updated. Currently package.json is generated at ng new and never do sync to latest dependencies.

I want something like ng doctor to solve it. The use-case images are below:

$ ng doctor # listing up dependency changes
$ ng doctor --write  # auto-patching on _compatible_ version (with semver ?)

Mention any other details that might be useful.