title: Unable to use DayPickerInput from React-Day-Picker with TypeScript
body: <p>Whenever I try to import DayPickerInput like below:</p>
  
  <pre><code>import DayPickerInput from 'react-day-picker/DayPickerInput';
  </code></pre>
  
  <p>I get the ts warning: "Could not find a declaration file for module 'react-day-picker/DayPickerInput."</p>
  
  <p>Looking at the module folder, looks like only DayPicker has types defined.</p>
  
  <p>When I try to use the require method instead like below:</p>
  
  <pre><code>var DayPickerInput = require('react-day-picker').DayPickerInput;
  </code></pre>
  
  <p>My project builds fine but I get a 2 runtime errors in the console when the component needs to be displayed:</p>
  
  <pre><code>Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in.
  
  Uncaught Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in. 
  </code></pre>
  
  <p>DayPickerInput is unusable for me right now.</p>