Added Twitter Chat Sessions

Import Jobs are:
- rake chatsessions:add (weekly or daily)
- rake questions:import (ev. 15 minutes)
- rake answers:import (ev. 15 minutes)

Path:
/chatsessions/:id

Actual there is still a problem with li:before styling
let's change ```(1..10).each``` to ```7.times```

It's a bit easier the read, and the questions will never be more than 7