Feature disable backup

This MR permits the user to disable backup cron task even if environment is `production`.

See merge request !111

Nginx ip

Add nginx ip as attribute

See merge request !112

Merge branch 'feature-customize-issue-closing-pattern' of https://gitlab.com/matthieu.o.vachon/cookbook-gitlab into matthieu.o.vachon/cookbook-gitlab-feature-customize-issue-closing-pattern

Conflicts:
	recipes/install.rb
	spec/install_spec.rb

Fix foodcritic

This MR fixes all foodcritic issues and removes some unused attributes at the same time. More specifically,

 * `support_email` - The support email is not used anymore in gitlab.
 * `standard_signin_enabled` - The sign enabled feature is already covered by the `signin_enabled` attribute.

See merge request !109

 * This settings is already covered by attribute signin_enabled it's
   a follow-up from foodcritic fixes.

 * This settings has been removed from gitlab and gitlab cookbook and it's
   a follow-up from foodcritic fixes.

Release 7.2

See merge request !107

Dev doc update

Updated Developer Doc to work for users who don't already have ruby installed.

The ruby bundled with chef can't properly run bundle install for gitlab due to the chef omnibus using an old openssl version, so if ruby isn't available we need to make sure to compile it.

Also added autoconf for the apt-get install, which is required for installing berks, and wasn't included in build-essential on Ubuntu 14.04

#52

See merge request !102

Use superior `postgres::ruby` recipe instead of database_postgresql_pg_gem

When the `external_database` attribute is set to `true`, the `database_postgresql_pg_gem` fails to install the `pg` gem on a vanilla Ubuntu machine because some packages (e.g. `build-essentials`) are not yet installed. The `postgres::ruby` recipe handles this correctly, so just reference that instead.

See merge request !99

Fixed typo

Fixed typo in build-essential package name

See merge request !106