title: Redux Form - multiple update function renders slow
body: <p>I am using redux-form 7.2.0.</p>
  
  <p>In my Project , I have 30 Fields in my form.</p>
  
  <p>Based on the First Field Value , i need to update some 20 fields. i call change action creator for 20 times. it takes more time to render these 20 fields. very slow.</p>
  
  <p>is there any way to make it fast in render?</p>
  
  <p>or</p>
  
  <p>is there any way to update multiple fields in single action?</p>
  
  <p>please help me to rectify this</p>