title: Ion checkbox binding two values
body: <p>I have been struggling with ion-checkboxes and I really need some help. I am developing a questionnaire that has true or false answers. I want the true and false to appear as ion-checkboxes. Something like this</p>
  
  <pre><code> &lt;ion-row&gt;
   &lt;ion-col size="1"&gt;
    &lt;ion-checkbox [checked]="option1" (ionChange)=change1()&gt;
    &lt;/ion-checkbox&gt;
   &lt;/ion-col&gt;
   &lt;ion-col&gt;True &lt;/ion-col&gt;
   &lt;ion-col size="1"&gt;
    &lt;ion-checkbox [checked]="option2" (ionChange)=change1()&gt;
    &lt;/ion-checkbox&gt;
   &lt;/ion-col&gt;
   &lt;ion-col&gt;False &lt;/ion-col&gt;
  &lt;/ion-row&gt;
  </code></pre>
  
  <p>I want the ionChange to ensure that only one checkbox is checked as true at a time. In other worlds, if the user selects true, then the false checkbox (option2) will automatically become false. If anyone can help I would really appreciate it. </p>