title: Linker command failed with exit code 1 (use -v to see invocation) with Swift 3
body: <p>I am working on building a Swift library and am <a href="https://github.com/Napalm-Framework/Napalm" rel="nofollow">hosting it on GitHub</a>.</p>
  
  <p>All was going fine until I added <a href="https://github.com/rhummelmose/BluetoothKit" rel="nofollow">BluetoothKit</a> to the project. I then got an Apple Mach-O Linker Error:</p>
  
  <pre><code>ld: warning: directory not found for option '-F/Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator10.0.sdk/Developer/Library/Frameworks'
  ld: /Users/calebklevetertest/Library/Developer/Xcode/DerivedData/Napalm-dblvhbjdwovurocsvzrzaxzkjjyw/Build/Products/Debug-iphonesimulator/Napalm.framework/Napalm compiled with older version of Swift language (2.0) than previous files (3.0) for architecture x86_64
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>
  
  <p>From reading the error it appears the issue somehow stems from the fact I am using Swift 3, but I can't figure out how to fix it.</p>
  
  <p>I did convert BluetoothKit to Swift 3 when I added it.</p>
  
  <p>There is one class that uses BluetoothKit and it is called <code>NPFBluetooth</code>.</p>
  
  <p>A couple things to note are 1) Even though the class is public, the compiler gives an error of 'unresolved identifier', 2) The class does not show in the auto-complete and 3) All the other classes work fine.</p>