title: TextInputMask for only positive numbers
body: <p>In my app I want user to enter 2 digit number.</p>
  
  <pre><code>&lt;TextInputMask
        placeholder="00" 
        ref={'Text2'}
        type={'only-numbers'} 
        maxLength={2}
        style = {styles.input2}
  /&gt;
  </code></pre>
  
  <p>However, user can press '-' (minus sign). How can I avoid this? 
  I already tried adding <strong>options={{mask : '999'}}</strong>.</p>