Make Coveralls opt-in

Due to looking for a value of 'false' whenever I run tests locally
without the `COVERAGE` env variable coverage is very slowly, still
calculated - it then aborts without doing anything because I'm not using
a CI setup.

This adds the setting in for Travis to opt in and should exclude
coverage work for anyone running tests locally.
Reduce size of Travis matrix

We excluded almost as much as we care about and adding COVERAGE created
a number of invalid combinations so this changes the matrix to include
the workable combinations of Ruby version and Gemfile.

COVERAGE is only on Ruby 1.9.3 whilst I confirm this is working
Revert to original .travis.yml and include one case
Merge pull request #2615 from fog/coverage_opt_in

Make Coveralls opt-in
[Brightbox] Add support for Cloud SQL service

This adds support for Brightbox's Cloud SQL DBaaS.

It is currently still part of the Compute service so all resources can
be managed from one connection to the service.
Update Flavours.rb with new M3 Instance Types

*Accouncement*: http://aws.typepad.com/aws/2014/01/aws-update-new-m3-features-reduced-ebs-prices-reduced-s3-prices.html
*Instance Types*: http://aws.amazon.com/ec2/instance-types/
Merge pull request #2618 from gaurish/patch-1

Update AWS flavors with new M3 Instance Types
Merge pull request #2620 from brightbox/cloud_sql

[Brightbox] Add support for Cloud SQL service
[vcloud_director] fix typo as per #2621
[Brightbox] Remove old #destroy request

All the "destroy" methods were renamed to "delete" but this file was not
removed.
Merge pull request #2622 from alphagov/2621_fix_typo

[vcloud_director] fix typo as per #2621
Merge pull request #2623 from brightbox/remove_old_destroy_request

[Brightbox] Remove old #destroy request
[openstack] image.update_image_members expects are incorrect #2627
Merge remote-tracking branch 'upstream/master'
[openstack] Fix for OpenStack flavor id calculation.
Merge pull request #2628 from radekg/master

[openstack] image.update_image_members expects are incorrect #2627
Use case-insensitive header access for Location.
Fix case sensitivity of the Content-type header.
Merge pull request #2634 from smashwilson/location-header

[rackspace | queues] Use case-insensitive header access for Location.