title: Swift Quick/Nimble - Wait for predicate to match
body: <p>I'm trying to convert the following block of code to Quick/Nimble with no success whatsoever</p>
  
  <pre class="lang-swift prettyprint-override"><code>XCTWaiter().wait(for: [XCTNSPredicateExpectation(predicate: NSPredicate(format: "height == 0"), 
                                                   object: vc.myView.frame)], 
                   timeout: 1)
  </code></pre>
  
  <p>I tried the following but the test does not pass </p>
  
  <pre class="lang-swift prettyprint-override"><code>waitUntil(timeout: 2) { done in
      expect(vc.myView.frame.height).to(equal(0))
      done()
  }
  </code></pre>
  
  <p>Thx in advance for your help!</p>