rspec double framework is default anyway
change mock to double for rspec 3.0
Convert specs to RSpec 3.0.4 syntax with Transpec

This conversion is done by Transpec 2.3.6 with the following command:
    transpec

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

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

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

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

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

* 1 conversion
    from: obj.should_not
      to: expect(obj).not_to

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