[#75] Fixed incorrect configuration for `discovery.ec2.group`

Fixing issue with AWS plugin, attribute for security group should be discovery.ec2.group
[#75] Upgrade the "elasticsearch-cloud-aws" plugin to 1.11.0
[#75] Improve the installation of the Fog gem

* Force installation of packages required for the Fog gem before the Chef run
* Use `run_action` for the Fog gem
[#75] Fixing `nil` for discovery_tags.each
[#75] Removed unneccessary code for `node.elasticsearch.discovery.ec2.tag`

Related: #66
[#75] Need to rescue the data attribute as it will be nil if your not using that recipe (like in dev)
[#75] Do not use `rescue` for `data['devices']` in `attributes/data.rb`

Revert "[#75] Need to rescue the data attribute as it will be nil if your not using that recipe (like in dev)"

This should not be needed:

    data = raise('BAM') rescue {}

    setting = data['devices'] || {}

    p setting

This reverts commit 45eb5ec133b28390c52c6c4437c964167b9fd350.
[#75] Fixed incorrect handling of the "elasticsearch-cloud-aws" plugin

The "elasticsearch-cloud-aws" plugin can't be named just "aws" in the plugin attributes,
as the plugin recipe will tries to install it, and fail,
causing Elasticsearch to restart on every Chef run.