title: Xcode Error: 'FirebaseCore/FirebaseCore.h' file not found
body: <p>After running <code>pod update</code> on my project, I am now getting the errors:</p>
  
  <blockquote>
    <p>'FirebaseCore/FirebaseCore.h' file not found</p>
  </blockquote>
  
  <p>and (I imagine associated):</p>
  
  <blockquote>
    <p>Could not build Objective-C module 'Firebase'</p>
  </blockquote>
  
  <p>I have tried deintegrating and installing pods multiple times, creating new workspaces (and making sure I am in workspace rather than project). I am not all that experienced in programming (yet!), but my podfile contains <code>use_frameworks!</code> in case that's of any help?</p>
  
  <p>I have also noticed that when I build my app I get a warning about not being able to find the pod.[AppName].xcconfig file, although the file isn't highlighted in red and appears to still be where it says?</p>