Add ability to skip installation step in create-react-app

[connorjsmith]

Is your proposal related to a problem?

We are planning on using lerna to manage multiple CRA applications. It wastes time to install a bunch of packages on every CRA call when we are planning on bootstrapping existing copies of dependencies into the project immediately after

Describe the solution you'd like

Add a new flag which skips the installation step, ie create-react-app app-name --no-install

[heyimalex]

Duplicate of #7568. I know that hasn't seen any action, but a duplicate won't change anything. I think we'd probably accept a PR if you're interested!