[Brightbox] Remove SQL instance snapshot attr

This didn't make it into the final API
Merge pull request #2689 from brightbox/remove_snapshot_attr

[Brightbox] Remove SQL instance snapshot attr
[core] Make the wait timeout truly global

The Rackspace helper changed the Fog.timeout global for all live tests
so the core test which expected "600" failed since it was now "2000"

Since it is a global setting it has been moved to the global test helper

It can now also be controlled by the FOG_TEST_TIMEOUT env variable.
Merge pull request #2690 from fog/make_timeout_change_global

[core] Make the wait timeout truly global
Set fast_finish on Travis CI
[Brightbox] Support Cloud SQL maintenance windows

Enables setting of `maintenance_weekday` and `maintenance_hour` values
to specify the maintenance window where updates may be applied to the
SQL instance.
Merge pull request #2692 from brightbox/maintenance_window_options

[Brightbox] Support Cloud SQL maintenance windows
[internetarchive] Correct test tagging

The provider is declaring itself as "internetarchive" which does not
match the tags "internet_archive" used on the tests.

Since we blacklist the tests that are run, it meant they continued to
run even if no credentials were present.
Merge pull request #2693 from fog/fix_internet_archive_tag

[internetarchive] Correct test tagging
Remove trailing whitespace
Merge pull request #2694 from fog/remove_trailing_whitespace

Remove trailing whitespace
[Brightbox] Require `fog/json` in compute

Since `fog-json` was extracted from `fog` it means if you rely on:

    require "fog/brightbox/compute"

`Fog::JSON` was not defined although it was supposed to be a supported
use case. This adds the missing require.
Require `json` or `xml` in provider cores

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
Merge pull request #2697 from fog/require_json_in_core

Require `json` or `xml` in provider cores