Updated example

Ok, the example made me waste 10+ hours trying to figure why my login didn't work.

Not all people understand 100% the library and the example is just plain wrong. The example used `secure: true` and copy-pasting it on a non-https site would fail to work always. Also, the **Options** doesn't include anything about **cookie secure**, so i updated the example to make it working and simple, and also updated **Options** to include `secure` defaults.
manually merge secure cookie notes and an example from #19 issue, thanks to @felixsanz

gist: secure cookies need https, docs didn't mention it