title: Adding ErrorText to material-ui Textfield moves other elements
body: <p>I have a signup form in a React app. I am using material-ui TextField and use the errorText property to add a message if there is an error in the input.</p>
  
  <pre><code>errorText={this.state.messages.emailMessage}
  </code></pre>
  
  <p>The state.messages.emailMessage is initially set to null and so TextField does not have the extra space for the message when the input is first rendered. </p>
  
  <p>When the message <em>is</em> added it moves the other elements.</p>
  
  <p>How can I allow space for the new node if it is needed so that the other elements are not moved? I tried setting the initial state of the message to ' ' but this colours the input red for error and doesn't work anyway!</p>