Convert specs to RSpec 3.0.0.beta1 syntax with Transpec

This conversion is done by Transpec 1.5.0 with the following command:
    transpec

* 999 conversions
    from: obj.should_receive(:message)
      to: expect(obj).to receive(:message)

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

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

* 33 conversions
    from: collection.should have(n).items
      to: expect(collection.size).to eq(n)

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

* 12 conversions
    from: obj.should_not_receive(:message)
      to: expect(obj).not_to receive(:message)

* 10 conversions
    from: obj.stub(:message)
      to: allow(obj).to receive(:message)

* 9 conversions
    from: be_true
      to: be_truthy

* 7 conversions
    from: it { should ... }
      to: it { is_expected.to ... }

* 6 conversions
    from: its(:attr) { }
      to: describe '#attr' do subject { super().attr }; it { } end

* 3 conversions
    from: be_false
      to: be_falsey

* 2 conversions
    from: it { should_not ... }
      to: it { is_expected.not_to ... }

* 2 conversions
    from: =~ [1, 2]
      to: match_array([1, 2])

* 2 conversions
    from: lambda { }.should
      to: expect { }.to