src/Tasks.php
public function postDeploy() {
    $terminus_site_env = $this->getPantheonSiteEnv();
    $pantheon_prefix   = getenv('TERMINUS_SITE');
    if ($terminus_site_env == $pantheon_prefix . '.develop' || $terminus_site_env == $pantheon_prefix . '.dev') {
      $drush_commands = [
        'drush_partial_config_import' => "terminus remote:drush $terminus_site_env -- config-import --partial -y",
        'drush_cache_clear' => "terminus remote:drush $terminus_site_env -- cr",
        'drush_entity_updates' => "terminus remote:drush $terminus_site_env -- entity-updates -y",
        'drush_update_database' => "terminus remote:drush $terminus_site_env -- updb -y",
        'drush_full_config_import' => "terminus remote:drush $terminus_site_env -- config-import -y",
      ];
      // Run the installation.
      $result = $this->taskExec(implode(' && ', $drush_commands))
        ->run();
    }
  }
public function postDeploy() {
    $terminus_site_env = $this->getPantheonSiteEnv();
    $pantheon_prefix   = getenv('TERMINUS_SITE');
    if ($terminus_site_env == $pantheon_prefix . '.develop' || $terminus_site_env == $pantheon_prefix . '.dev') {
      $drush_commands = [
        'drush_partial_config_import' => "terminus remote:drush $terminus_site_env -- config-import --partial -y",
        'drush_cache_clear' => "terminus remote:drush $terminus_site_env -- cr",
        'drush_entity_updates' => "terminus remote:drush $terminus_site_env -- entity-updates -y",
        'drush_update_database' => "terminus remote:drush $terminus_site_env -- updb -y",
        'drush_full_config_import' => "terminus remote:drush $terminus_site_env -- config-import -y",
      ];
      // Run the installation.
      $result = $this->taskExec(implode(' && ', $drush_commands))
        ->run();
    }
  }
public function postDeploy ( ) { $ terminus_site_env = $ this -> getPantheonSiteEnv ( ) ; $ pantheon_prefix = getenv ( 'TERMINUS_SITE' ) ; if ( $ terminus_site_env == $ pantheon_prefix . '.develop' || $ terminus_site_env == $ pantheon_prefix . '.dev' ) { $ drush_commands = [ 'drush_partial_config_import' => "terminus remote:drush $terminus_site_env -- config-import --partial -y" , 'drush_cache_clear' => "terminus remote:drush $terminus_site_env -- cr" , 'drush_entity_updates' => "terminus remote:drush $terminus_site_env -- entity-updates -y" , 'drush_update_database' => "terminus remote:drush $terminus_site_env -- updb -y" , 'drush_full_config_import' => "terminus remote:drush $terminus_site_env -- config-import -y" , ] ; // Run the installation. $ result = $ this -> taskExec ( implode ( ' && ' , $ drush_commands ) ) -> run ( ) ; } }
Clean up state of Pantheon dev & develop environments after deploying.

Run this by adding the line:
robo post:deploy

right after this line:
robo pantheon:deploy --y

in your .circleci/config.yml file.
Clean up state of Pantheon dev & develop environments after deploying .