RSpec: Convert to RSpec 2.14.7 syntax via Transpec

This conversion is done by Transpec 1.13.0 with the following command:
    transpec

* 423 conversions
    from: obj.should
      to: expect(obj).to

* 181 conversions
    from: == expected
      to: eq(expected)

* 27 conversions
    from: obj.should_not
      to: expect(obj).not_to

* 8 conversions
    from: > expected
      to: be > expected

* 5 conversions
    from: < expected
      to: be < expected

* 3 conversions
    from: =~ /pattern/
      to: match(/pattern/)

* 3 conversions
    from: its(:attr) { }
      to: describe '#attr' do subject { super().attr }; it { } end
RSpec: Tweaked syntax to leverage be_nil & be_empty.