Vagrant dying due to Faraday gem

Vagrant was croaking after the upgrade to 1.5. The error:

$ vagrant up
  Vagrant failed to initialize at a very early stage:

  The plugins failed to load properly. The error message given is
  shown below.

  undefined method `register_middleware' for #<Faraday::Connection:0x00000100ba8780>

The fix:

$ sudo /Applications/Vagrant/embedded/bin/gem uninstall faraday
$ sudo /Applications/Vagrant/embedded/bin/gem install faraday --version 0.8.5

Hat tip to Berkshelf Issue #979 and Vagrant Issue #3128