I have found a solution 
. The problem is that ansible tries to set a root password where no password yet exists. What you have to do to get rid of the issue is: ssh to your remote server. Change to the root user sudo su - root open up the .my.cnf file. It should be in the root of your root user. Change your password to match the password you have set in group_vars/production/vault.yml. After you did that save the file and try to provision again. This should resolve the issue.
I hope someone experiencing the same problem will read this and have a nice day!