title: IBDesignable Errors When Adding to Tests Target
body: <p>I have a simple <code>UIButton</code> subclass that implements <code>IBDesignable</code> with an <code>IBInspectable</code> var:</p>
  
  <pre><code>@IBDesignable class Button: UIButton {
      @IBInspectable var borderColor: UIColor = UIColor.whiteColor() {
          didSet { layer.borderColor = borderColor.CGColor }
      }
  }
  </code></pre>
  
  <p>I am not using this within a framework and it is working in Interface Builder as intended, however, once I add this subclass to my <code>Tests</code> target, it stops rendering live and I get the following errors:</p>
  
  <pre><code>Main.storyboard: error: IB Designables: Failed to update auto layout status: dlopen(TestTests.xctest, 1): Library not loaded: @rpath/XCTest.framework/XCTest
  Referenced from: TestTests.xctest
  Reason: image not found
  
  Main.storyboard: error: IB Designables: Failed to render instance of Button: dlopen(TestTests.xctest, 1): Library not loaded: @rpath/XCTest.framework/XCTest
  Referenced from: TestTests.xctest
  Reason: image not found
  </code></pre>
  
  <p>If I remove <code>IBDesignable</code> and the <code>IBInspectable</code> vars, the errors go away - unfortunately so does the live rendering in Interface Builder.</p>
  
  <p>How do I test against an <code>IBDesignable</code> class without these errors?</p>