This commit adds the initial support for Google Cloud SQL:
- Adds a new service 'SQL' to the existing 'Google' provider
- Creates new shared methods to be reused by different services
- Add requests, models and tests for Tiers
Since `fog-json` was extracted from `fog` it means if you rely on:
require "fog/provider/compute"
`Fog::JSON` was not defined although it was supposed to be a supported
use case.
This adds the requires for JSON or XML based APIs based on a quick scan
of each provider to declare the required part.
AWS seems to be relying on both. Which is nice.
Providers relying on native code dependencies
