title: styled-components typescript error with Material-UI component
body: <p>Using typescript and want to set styling for Material UI component with styled-components.<br>
  But type error happens with StyledComponent showing <code>Type '{ children: string; }' is missing the following properties</code></p>
  
  <pre><code>import React, { PureComponent } from 'react';
  import styled from 'styled-components'; // ^4.1.3
  import { Button } from '@material-ui/core'; // ^3.9.1
  
  class TestForm extends PureComponent {
    render() {
      return (
        &lt;&gt;
          &lt;Button style={{ backgroundColor: 'red' }}&gt;Work&lt;/Button&gt;{/* OK  */}
  
          &lt;StyledButton&gt;Doesn't work&lt;/StyledButton&gt;{/* Type Error happens here &lt;=============== */}
          {/**
            Type '{ children: string; }' is missing the following properties from type 'Pick&lt;Pick&lt;(ButtonProps &amp; RefAttributes&lt;Component&lt;ButtonProps, any, any&gt;&gt;) | (ButtonProps &amp; { children?: ReactNode; }), "form" | "style" | "title" | "disabled" | "mini" | ... 279 more ... | "variant"&gt; &amp; Partial&lt;...&gt;, "form" | ... 283 more ... | "variant"&gt;': style, classes, className, innerRef [2739]
           */}
        &lt;/&gt;
      );
    }
  }
  
  const StyledButton = styled(Button)`
    background: blue;
  `;
  
  export default TestForm;
  </code></pre>
  
  <p>It is showing children prop is missing.<br>
  I have tried the following too but still doesn't work.</p>
  
  <pre><code>const StyledButton = styled(Button)&lt;{ children: string; }&gt;`
    background: blue;
  `;
  </code></pre>
  
  <p>Does anyone know how to use Material UI with styled-components in typescript?</p>