Create liquibase user with all powers. Execute these commands ON THE VAGRANT BOX. Log-in to the box, execute "mysql" then enter each of the following lines one by one.
CREATE USER 'liquibase'@'localhost' IDENTIFIED BY 'P@ssw0rd1';
GRANT ALL PRIVILEGES ON *.* TO 'liquibase'@'localhost' WITH GRANT OPTION;
CREATE USER 'liquibase'@'%' IDENTIFIED BY 'P@ssw0rd1';
GRANT ALL PRIVILEGES ON *.* TO 'liquibase'@'%' WITH GRANT OPTION;
FLUSH PRIVILEGES;