Initial attempt at Vimrunner::RSpec
Custom configuration for RSpec helper
Remove leftover require
Rethink some of the logic
Always execute examples in a separate directory

It's a safe choice and the most common way to write tests will probably
be through intermediate files, so it makes some sense to do this by
default.
Remove Testing::tmpdir, since it'll be used only in rspec helper
Merge branch 'rspec-integration'

* rspec-integration:
  Remove Testing::tmpdir, since it'll be used only in rspec helper
  Always execute examples in a separate directory
  Rethink some of the logic
  Remove leftover require
  Custom configuration for RSpec helper
  Initial attempt at Vimrunner::RSpec