* correctly set dependencies in configuration
* update RPM repo key
* add tests for passenger installation as nginx module
* update test matrix

- currently you're forced to define extra states if you opt to install nginx with passenger,
 if you want the same outcome for passenger and nginx installs with equivalent config
- passenger is an extra module on top of nginx, makes no sense to end up with less configuration by default

First implementation of TOFS for:
nginx_config, passenger_config, servers_config and snippets
Introduced tplroot on modified files as well
Fixed GH link of nginx.conf file in docs/TOFS_pattern.rst
Fixed test for snippets name pillar

BREAKING CHANGE: all previous `nginx` based configurations must be reviewed;
`nginx.ng` usage must be promoted to `nginx` and any uses of the original
`nginx` will have to be converted.