Uninitialized constant RSpec::Core::CommandLine

`RSpec::Core::CommandLine` was merged into `RSpec::Core::Runner in 3.0.0.rc1`.  I poked around and added some code that fixed the uninitialized constant error. 

Please note: I was unable run the test suite (even before modifying any code) because I kept getting this error:
`forker.rb:29:in 'write': not opened for writing (IOError)`.  I tried but now I need to move on to other things.  Hope this helps!