Remove Ruby dependency used to process yaml files

[jordimas]

We are currently need to install the full Ruby development environment to install:

gem install i18n-translators-tools

and be able to process projects like Discourse and Mastodoon.

Instead, it will be better to use yaml2po from translate-toolkit if it is possible. Currently it does NOT processes the project Discourse, we will need to fix yaml2po in upstream.

[pereorga]

Un altre projecte que fa servir YAML, amb una estructura i format una mica peculiar:

https://github.com/opf/openproject/tree/dev/config/locales

Són bastantes cadenes.

[pereorga]

I un altre: https://github.com/sharetribe/sharetribe/blob/master/config/locales/admin_old/ca.yml

Tant aquest com l'anterior les cadenes pengen del codi d'idioma.