Added TLS support to webdev serve. (#564) (#565)

Helps with issue: #564 

- Added option `tls-cert-chain`
- Added option `tls-cert-key`

By adding the above to flags to `webdev serve` users are able to launch the development server listening for HTTPS requests.

Known Issue:
The output line will show 127.0.0.1 regardless of what the `--hostname` flag is set to. However, the server will listen to all hostnames regardless. I did not see a place to set the hostname in HttpMultiServer's loopbackSecure to inject the hostname. Perhaps this issue could be resolved with a change in that output line?
8 files changed