Computable inputs syntax in composer

Current syntax for computable inputs is hard to read it could be improved from:

 wait_cmd:
        computable:
          func: "mysql -p{{env['MYSQL_ROOT_PASSWORD']}} -uroot -e 'SELECT 1'"
          connections:
            - mysql::env::NO_EVENTS

to:

wait_cmd:
        computable: "mysql -p{{mysql::env['MYSQL_ROOT_PASSWORD']}} -uroot -e 'SELECT 1'"