As the tile says, updates the composer dependencies by running composer update. The following changes were made:

• Updating paragonie/random_compat (v2.0.12 => v2.0.15)
• Updating defuse/php-encryption (v2.1.0 => v2.2.0)
• Updating paragonie/sodium_compat (v1.6.1 => v1.6.3)
• Updating symfony/debug (v3.4.7 => v3.4.11)
• Updating symfony/web-link (v3.4.7 => v3.4.11)
• Updating joomla/filter (1.3.3 => 1.3.5)
• Updating joomla/input (1.2.1 => 1.2.3)
• Updating zendframework/zend-diactoros (1.7.1 => 1.7.2)
• Updating symfony/polyfill-mbstring (v1.7.0 => v1.8.0)
• Installing symfony/polyfill-ctype (v1.8.0)
• Updating symfony/console (v3.4.7 => v3.4.11)
• Updating symfony/yaml (v3.4.7 => v3.4.11)
• Removing joomla/application (dev-2.0-dev 9fc3da5)
• Installing joomla/application (dev-2.0-dev ca4c5a1)
• Removing joomla/authentication (dev-2.0-dev aaaa50a)
• Installing joomla/authentication (dev-2.0-dev 62014f2)
• Removing joomla/console (dev-master b625aeb)
• Installing joomla/console (dev-master 2843800)
• Removing joomla/database (dev-2.0-dev be0ec4f)
• Installing joomla/database (dev-2.0-dev ccf0eaa)
• Removing joomla/event (dev-2.0-dev 71d0e41)
• Installing joomla/event (dev-2.0-dev 9092ee2)
• Removing joomla/image (dev-2.0-dev 20cf764)
• Installing joomla/image (dev-2.0-dev 0222c4a)
• Removing joomla/ldap (dev-2.0-dev 19f5041)
• Installing joomla/ldap (dev-2.0-dev f19a37a)
• Removing joomla/registry (dev-2.0-dev 5b32d71)
• Installing joomla/registry (dev-2.0-dev d6f0d05)
• Removing joomla/session (dev-2.0-dev f7cca05)
• Installing joomla/session (dev-2.0-dev 8dd6219)