create conf files if they do not exist

[jbouzekri]

This a fix for : #6

Moreover, I want to point out that I had to generate the locale in my box to make this role work. You should maybe add this information to the README.

[bgruening]

ping @natefoo

[natefoo]

Ah, this was the exact problem encountered by a number of participants in the Ansible workshop at the Galaxy Community Conference 2016. It's a shame I hadn't found this before!

I am not sure that creating the configs is the correct fix here - I would think it'd be better to ensure that the locales are configured properly first so that the config files are properly generated when the postgresql packages are installed.