.rspec file needs minor change on formatter name for rspec1 to rspec2 update

[helloanh]

rspec1 to rspec2 update needs to change .rspec file or your TDD won't work for rails/ruby.

If your.rspec file only have:
--color
and I was still getting this error.
You need to change it to this:
--format documentation --color

This issue was opened and solved here on stackoverflow.