title: Cant 'observeOn' main thread with RxKotlin
body: <p>I'm trying to observe observable on main thread by using:</p>
  
  <pre><code>    // Kotlin Code
      Observable
        .observeOn(AndroidSchedulers.mainThread())
  </code></pre>
  
  <p>but I'm getting following error:</p>
  
  <pre><code>    Type Mismatch:
        Required: rx.Scheduler!
        Found: io.reactivex.Scheduler!
  </code></pre>
  
  <p>The Observable I'm subscribing to is from a Library that is written in Java and therefore uses RxJava.</p>
  
  <p>Am i being stupid and missing something? I'm puzzeled :$</p>
  
  <p>Thanks in advance :)</p>