title: Can't import IResolvers from graphql-tools
body: <p><code>import { IResolvers } from &quot;graphql-tools&quot;;</code>
  I was trying to import IResolvers from graphql-tools and got the message Module: <em>'&quot;../node_modules/graphql-tools&quot;' has no exported member 'IResolvers'</em>.</p>
  <p>My dependencies are:&quot;apollo-server-express&quot;: &quot;^3.1.2&quot;,&quot;graphql&quot;: &quot;^15.5.1&quot;, &quot;graphql-tools&quot;: &quot;^8.1.0&quot;</p>
  <p>Is this because I am on apollo 3 instead of apollo 2 which has IResolver?</p>