title: Updating periodically with RxSwift
body: <p>I use the following setup to retrieve objects (e.g. GitHub issues) from an API. This works fine.</p>
  
  <pre><code>let provider: RxMoyaProvider&lt;GitHub&gt;
  let issues: Driver&lt;[IssueViewModel]&gt;
  
  init(provider: RxMoyaProvider&lt;GitHub&gt;) {
      self.provider = provider
      issues = provider.request(.Issue)
                .mapArray(Issue.self, keyPath: "issues")
                .asDriver(onErrorJustReturn: [])
                .map { (models: [Issue]) -&gt; [IssueViewModel] in
                    let items = models.map {
                        IssueViewModel(name: $0.name,
                            description: $0.description
                        )
                    }
                    return items
                }
  }
  </code></pre>
  
  <p>Now I'd like to periodically update the list of issues (e.g., every 20 seconds). I thought about an <code>NSTimer</code> to accomplish this task, but I guess there might be a clean(er) solution (i.e. in a Rx manner) that I didn't think about.</p>
  
  <p>Any hint in the right direction is highly appreciated.</p>