title: auto_compaction with ember-pouch
body: <p>I want to use ember-pouch in an electron-app. I just need a local indexedDb without a CouchDB backend. When I use the database-constructor with the argument auto_compaction to true the database is not working as I expect it to. I would expect that every write operation in the localDb triggers a compact() operation. This would wipe out every document with a _delete flag on it. But that doesn't happen The database still holds deleted documents.</p>
  
  <p>My application adapter in ember:</p>
  
  <pre><code>import { Adapter } from 'ember-pouch';
  import PouchDB from 'pouchdb';
  import config from 'em-trispo/config/environment';
  import Ember from 'ember';
  
  function createDb() {
    let localDb = config.emberPouch.localDb;
    let db = new PouchDB(localDb, {auto_compaction: true});
    return db;
  }
  
  export default Adapter.extend({
    init() {
      this._super(...arguments);
      this.set('db', createDb());
    }
  });
  </code></pre>