title: Branch.io deep link handler not being called with proper metadata
body: <p>This is the situation: if I click one of the links that I have with custom key/values associated with it, my callback from <code>initSessionWithLaunchOptions:andRegisterDeepLinkHandler</code> is being triggered ok, but ‘params’ only contain the custom key/values in the case the app is fresh opened from the link. In the case the app was already running in background and I click the link, the callback is called but no parameters are present. This was working a few weeks ago and now seems to stop working. I tried upgrading to iOS SDK 0.12.1 too but no luck yet.</p>
  
  <p>As a workaround, I’m trying doing a delayed sequence of calls to <code>Branch.getInstance().getLatestReferringParams()</code> after the app becomes active and sometimes I’m getting the parameters from there, but it’s not deterministic, sometimes it takes 2 seconds, sometimes 10 seconds, sometimes never.
  @AlexBauer Here's the parts of the app delegate. Btw, I don't have facebook integration in the app:</p>
  
  <pre class="lang-swift prettyprint-override"><code>func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -&gt; Bool {
  
      let branch: Branch = Branch.getInstance()
      branch.initSessionWithLaunchOptions(launchOptions, andRegisterDeepLinkHandler: { params, error in
          if (error == nil) {
              print(params)
              self.tryInviteFlow(params)
          } else {
              print(error.localizedDescription)
          }
      })
  }
  
  func application(application: UIApplication, continueUserActivity userActivity: NSUserActivity, restorationHandler: ([AnyObject]?) -&gt; Void) -&gt; Bool {
      // pass the url to the handle deep link call
      return Branch.getInstance().continueUserActivity(userActivity);
  }
  </code></pre>