title: az login on specific subscription
body: <p>If you want to connect to a specific subscription with Az.Accounts, you do something like:</p>
  <pre><code>Connect-AzAccount -SubscriptionId &lt;guid&gt; etc...
  </code></pre>
  <p>I see that there is no possibility of specifying the SubscriptionId with <code>az login</code>.</p>
  <p>If my account for example manages multiple subscriptions, what would happen when listing all resource groups?</p>
  <p>How can I login on only one subscription?</p>