title: Cannot find attachSchema property on Mongo.Collection with angular2-meteor
body: <p><strong>Here is my problem :</strong></p>
  
  <p>I want to use the power of simple-schema to be able to check my inserts against the following schema :</p>
  
  <pre><code>let UprocSchema = new SimpleSchema({
      "name": { type : String, label: "Nom Uproc" },
      "label": { type : String, label: "Libellé Uproc" },
      "status": { type : String, label: "Status UPR" }
  });
  </code></pre>
  
  <p>For some reason I ignore, even if the SimpleSchema seems to be well instanciated, I cannot use the attachSchema property on Mongo.Collection.</p>
  
  <p><strong>Here is my code :</strong></p>
  
  <pre><code>let repo_collection = new Mongo.Collection('repository');
  export const Repository = new MongoObservable.Collection&lt;Uproc&gt;('repo_collection');
  repo_collection.attachSchema( UprocSchema );
  </code></pre>
  
  <p><strong>Here is my error messages :</strong></p>
  
  <blockquote>
    <p>Property 'attachSchema' does not exist on type 'Collection&lt;{}>'.</p>
    
    <p>TypeError: repo_collection.attachSchema is not a function</p>
  </blockquote>