title: Is it possible to use Observable<Double>.interval in RxSwift?
body: <p>Hi I have a question here, all the docs I found on RxSwift so far are using observable interval as below:</p>
  
  <pre><code>let subscription = Observable&lt;Int&gt;.interval(0.3, scheduler: scheduler)
      .subscribe { event in
          print(event)
      }
  
  NSThread.sleepForTimeInterval(2)
  
  subscription.dispose()
  </code></pre>
  
  <p>Now I have the need to implement a <code>Observable&lt;Double&gt;.interval</code> timer, I would like to a Double value in my subscribeNext calls from Observable.</p>
  
  <p>After change above code to <code>Double</code> as a testing, I have an error saying <code>Type Observable&lt;Double&gt; has no member IntegerLiteralType</code> , anyone knows how to implement this in RxSwift?</p>