title: There is an error popped up when typing "import FBSDKLoginKit"
body: <p>I have strictly followed the percedures shown on website, wanting to use facebook account to login on my designed app. But when I type <code>import FBSDKLoginKit</code> below the sentence <code>"import FBSDKCoreKit"</code>, system gives me an error saying that: <code>Could not build an Objective-C module 'FBSDKLoginKit'</code>.  I do not know why there is no <code>error</code> on the tutorial video but it is for me. <code>(I'm using swift to implement my app)</code>
     Thank you so much for your help. </p>