Convert specs to RSpec 3.1.7 syntax with Transpec

This conversion is done by Transpec 3.0.8 with the following command:
    transpec spec/classes spec/defines spec/unit

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

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

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

* 1 conversion
    from: it { should_not ... }
      to: it { is_expected.not_to ... }

For more details: https://github.com/yujinakayama/transpec#supported-conversions