title: async/await throwing error in es2015
body: <p>Async/ Await throwing error while compilation. Im currently using babel with presets - es2015, &amp; plugin - transform-async-to-generator. Check my code below</p>
  
  <pre><code>async function verifyUserAlreadyExists(phone, email) {
      try {   
          db.collection("users").find({
          $or:{"contact_details.phone": phone, "contact_details.email": email}
          }, (err, cursor)=&gt;{
                  await cursor.count() &gt;= 1;
          });
      }catch(err) {
          console.log("Verify User Exists:"+JSON.stringify(err));
      }
   }
  
  export default {
      getAllUsers: (request, reply) =&gt; {
          db.collection("users").find({}).toArray((err, users) =&gt; {
              reply(users);
          });  
      },
      insertNewUser: (request,reply) =&gt; {
          let userAlreadyExists = await verifyUserAlreadyExists("7259769413");
          console.log(userAlreadyExists);
      }   
  }
  </code></pre>