Sorting failed when using `.attr()`

[captainamerican]

If you add .attr() to a styled component, the plugin ignores the component.

To Reproduce
The following code will be ignored and the properties not sorted:

const aDiv = styled.div.attrs({ className: "SuperImportantDiv" })`
  color: red;
  border: 1px blue solid;
`;

Expected behavior
It should identify the styled component and sort the properties normally.

Screenshots
N/A

Desktop (please complete the following information):

• OS: OSX

Smartphone (please complete the following information):

• Doesn't matter

Additional context
Great plugin otherwise!