title: How to update the store after a mutation with relay?
body: <p>I'm struggling to figure out how this should work. I have an application that has a current user, so, the topmost query looks like this:</p>
  
  <pre><code>  query AppQuery {
      currentUser {
        id
        email
        ...Account_currentUser
        ...AccountEdit_currentUser
      }
    }
  </code></pre>
  
  <p><code>AccountEdit_currentUser</code> is defined this way:</p>
  
  <pre><code>export default createFragmentContainer(AccountEdit, {
    currentUser: graphql`
      fragment AccountEdit_currentUser on User {
        email
        name
        nickName
      }`
  })
  </code></pre>
  
  <p>on the <code>AccountEdit</code> component. That component commits this mutation:</p>
  
  <pre><code>  mutation AccountEditMutation($email: String!, $name: String!, $nickName: String!) {
      updateAccount(input: {email: $email, name: $name, nickName: $nickName}) {
        accountUpdated
        currentUser {
          id
          email
          name
          nickName
        }
      }
    }
  </code></pre>
  
  <p>After that happens, the server returns the correct values for email, name, nickName, etc. How should those new values end up in the store? Because it doesn't seem to automatic. Do I need to write a custom updater? and update config? I tried it a few times but I couldn't get anywhere close to something that even throws a reasonable error.</p>