Support writing full tests in inspec shell

[arlimus]

At the moment it is not possible to start an inspec shell and paste either a control or a describe block and have it execute and report results.

I.e:

inspec shell

And then enter:

describe file('/not/here') do
   it { should_not exist }
end

which will only result in:

=> [["describe", [File /not/here], #<Proc:0x000000013f3850@(pry):1>]]

The desired output should be:

1. A print of the execution using the default cli formatter, without the additonal profile context and version. i.e.:

     ✔  ssh-1: Allow only SSH Protocol 2

2. The test should return a result object, which has a result value embedded.