module-spec pair creation seemed to have never worked in ST3

RSpec plugin v2 is shipped with the fixed and improved new module-spec pair creation

* Command Palette -> RSpec: create new module
* input the name of the class with optional namespace (see below)

* input `A/B/C` or `A::B::C` will generate

*c.rb*

```ruby
module A
  module B
    class C

    end
  end
end
```

*c_spec.rb*

```ruby
require 'spec_helper'

describe A::B::C do

end
```
