Use valid cert for HTTPS in development

Created by: radi-cho

Is this a bug report?

No. This is a question (for now) or discussion.

Which terms did you search for in User Guide?

HTTPS

Environment

1. OS: Windows 10
2. node -v: 8.4.0
3. yarn --version: 0.27.5/1.0.0
4. I haven’t ejected
5. Browser: Chrome 62

Steps to Reproduce:

1. Create a project
2. Run: 'set HTTPS=true&&yarn start' (or npm start)
3. Open https://localhost:3000 in the browser

Expected Behavior

Safe and secure HTTPS connection

Actual Behavior

Error message:

Your connection is not private

Main Question:

What I'm doing wrong and how to open secure connection without seeing errors or "unsafe connection warnings"?