Tighten params around attachment creation
Convert specs to RSpec 2.99.1 syntax with Transpec

This conversion is done by Transpec 2.3.8 with the following command:
    transpec -f

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

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

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

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

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

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

* 1 conversion
    from: obj.stub(:message)
      to: allow(obj).to receive(:message)

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