title: How to focus to text input without using ref?
body: <p>I have try using focus and also autofocus.Using React Native 0.43
  Example simple scenario </p>
  
  <pre><code>&lt;ListItem
   title="Username"
   textInput={true}
   textInputValue={this.state.userName}
   textInputSecureTextEntry={false}
   textInputOnChangeText={this
   .bindData
   .bind(this, 'userName')}
   textInputAutoFocus={this.state.userNameAutoFocus}
   textInputFocus={this.state.userNameFocus}
   textInputKeyboardType="default"
   textInputPlaceHolder="Type your Username Here"
   textInputContainerStyle={styles.inputFormStyle}
   textInputOnSubmitEditing={this
   .nextFormComponent
   .bind(this, 'userPassword')}
   textInputReturnKeyType="next" /&gt; 
  </code></pre>
  
  <p><a href="https://pastebin.com/Tw67PjjP" rel="nofollow noreferrer">Source Code</a>
  <a href="https://pastebin.com/iWDNUnWs" rel="nofollow noreferrer">Source Code NPM</a></p>