uninitialized constant Rspec

From the error:

uninitialized constant Rspec (NameError)

In your Cipher spec, you have misspelled RSpec as Rspec. Ruby identifiers are case-sensitive, and you haven't defined Rspec, hence the error.

I was getting this error because rubymine was trying to run "tests" instead of "rspecs". When I changed the run configuration to run an RSpec instead of a Test everything worked fine.