Remove unexpected gem dependency

'>= 2.14.0.rc'
Installing rspec-core (3.0.0.beta1)
Installing rspec-support (3.0.0.beta1)
Installing rspec-expectations (3.0.0.beta1)
Installing rspec-mocks (3.0.0.beta1)
Installing rspec (3.0.0.beta1)

'>= 2.14.0′
Installing rspec-core (2.14.7)
Installing rspec-expectations (2.14.4)
Using rspec-mocks (2.14.4)
Using rspec (2.14.1)