Support HTTPS

[levithomason]

From node-livereload api options:

https is an optional object of options to be passed to https.createServer (if not provided, http.createServer is used instead)

Their test shows how it works. You pass an https object with cert / key properties, then the livereload script is served over https with those.

Currently, when I pass this object express-livereload still serves the script over http.

[levithomason]

Looking a little closer, this was introduced in ver 0.3.6, express-livereload is currently using 0.3.3.