~/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/spring-1.3.0/lib/spring/configuration.rb:37:in `pwd': No such file or directory - getcwd (Errno::ENOENT)
The error is caused by an existing Rails Spring process running in the background.
You can easily solve this by running
ps ax | grep spring to find the process id and then kill it.
There's an issue on the Rails GitHub about this: https://github.com/rails/spring/issues/247