vapor toolbox broken after upgrading swift : <p>Vapor toolbox is crashing when trying to use it after upgrading to Swift 3.1.</p>

<pre><code>dyld: lazy symbol binding failed: Symbol not found: __TTSfq4n_s___TFVSS13CharacterView38_measureExtendedGraphemeClusterForwardfT4fromVVSS17UnicodeScalarView5Index_Si
  Referenced from: /usr/local/bin/vapor
  Expected in: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/libswiftCore.dylib

dyld: Symbol not found: __TTSfq4n_s___TFVSS13CharacterView38_measureExtendedGraphemeClusterForwardfT4fromVVSS17UnicodeScalarView5Index_Si
  Referenced from: /usr/local/bin/vapor
  Expected in: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx/libswiftCore.dylib
</code></pre>
