How can I update the current Drupal 8 version of the droplet?

Hello,

I just created a 1 click Drupal 8 app droplet and wanted to update it to the most recent core version using SSH.

Here is what I did and what the result was.

Any help is really appreciated.

/var/www/html/drupal# drush pm-update -n
Command pm-update needs a higher bootstrap level to run - you will   [error]
need to invoke drush from a more functional Drupal environment to run
this command.
The drush command 'pm-update' could not be executed.                 [error]
Drush was not able to start (bootstrap) the Drupal database.         [error]
Hint: This may occur when Drush is trying to:
 * bootstrap a site that has not been installed or does not have a
configured database. In this case you can select another site with a
working database setup by specifying the URI to use with the --uri
parameter on the command line. See `drush topic docs-aliases` for
details.
 * connect the database through a socket. The socket file may be
wrong or the php-cli may have no access to it in a jailed shell. See
http://drupal.org/node/1428638 for details.

Drush was attempting to connect to:
 Drupal version         :  8.1.3
 Site URI               :  http://default
 Database driver        :  mysql
 Database hostname      :  localhost
 Database port          :
 Database username      :  drupal
 Database name          :  drupal
 PHP configuration      :  /etc/php5/cli/php.ini
 PHP OS                 :  Linux
 Drush script           :  /usr/local/bin/drush
 Drush version          :  8.1.2
 Drush temp directory   :  /tmp
 Drush configuration    :
 Drush alias files      :
 Drupal root            :  /var/www/html/drupal
 Drupal Settings File   :  sites/default/settings.php
 Site path              :  sites/default
 Sync config path       :  sites/default/files/config_6ZGKwLLTkFulS
                           a3WyKkTdMUo7Tb2jkQLP7aVLV0SklE5ElSV2cYC_
                           7HJbGD8W_sMaNoNWP2iHQ/sync