Convert specs to RSpec 3.1.4 syntax with Transpec

This conversion is done by Transpec 2.3.7 with the following command:
    transpec

* 38 conversions
    from: == expected
      to: eq(expected)

* 30 conversions
    from: it { should ... }
      to: it { is_expected.to ... }

* 8 conversions
    from: obj.should
      to: expect(obj).to

* 2 conversions
    from: obj.stub(:message)
      to: allow(obj).to receive(:message)

* 1 conversion
    from: lambda { }.should
      to: expect { }.to

For more details: https://github.com/yujinakayama/transpec#supported-conversions