Upgrading ruby version and gems
Convert specs to RSpec 3.1.7 syntax with Transpec

This conversion is done by Transpec 3.0.3 with the following command:
    transpec

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

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

* 4 conversions
    from: Klass.any_instance.stub(:message)
      to: allow_any_instance_of(Klass).to receive(:message)

* 1 conversion
    from: be_true
      to: be_truthy

* 1 conversion
    from: lambda { }.should
      to: expect { }.to

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