Hardcoded deployer db_user and db_name in postgres provisioning

[wojciechczerniak]

• Deployer version: master
• Deployment OS: Ubuntu 20 LTS

Although user is prompted for database user name, it's not used by Postgresql provisioning. deployer db_user and deployer db_name are hardcoded:

deployer/recipe/provision/databases.php

Lines 61 to 62 in 6d759ef

	run('sudo -u postgres createuser deployer');
	run('sudo -u postgres createdb deployer');

Shouldn't it be closer to this?

- run('sudo -u postgres createuser deployer'); 
- run('sudo -u postgres createdb deployer'); 
+ run('sudo -u postgres createuser {{db_user}}'); 
+ run('sudo -u postgres createdb {{db_name}}');