[google][compute] Update to API v1

Simplify attachment of boot disk, get_as_boot_disk no longer needed
Add missing Disk.get_object method
Allow setting deviceName when attaching a disk
Add disks mocks
[google] Handle 500 errors from GCE
[google][compute] Add support for blank disks (i.e. remove code that required only image or snapshot based disks to be created)
Add support for AWS VPC Network ACLs
reject unnecessary methods creation and clean up remove_method
[aws|iam] Mock delete_server_certificate raises NotFound appropriately.
Moved #compact to a sesparate line to make it a little more obvious
Servers with a password locked root user have a nil @password.
Merge pull request #2497 from elight/optional_root_lock

[Rackspace | Compute] 1.8.7 fix plus better passwd -l handling
refactor DataPipeline format conversion, allowing for arrays of refs
Merge pull request #2490 from drcapulet/drcapulet/vpc-network-acls

Add support for AWS VPC Network ACLs
Merge pull request #2496 from allomov/remove-method-question

Reject unnecessary methods creation in Core Collection
[aws|elb] Mimic create_load_balancer mock

Mimic behaviour like the real one, as a availability_zones can be nil
and not when mocking.
Merge pull request #2494 from maestrodev/gce-v1

[google|compute] Update to Google Compute Engine API v1
[google|compute] Readme update.
Merge pull request #2499 from mattgillooly/aws_data_pipeline_allows_array_refs

refactor DataPipeline format conversion, allowing for arrays of refs
Merge pull request #2500 from josacar/master

[aws|elb] Mimic real behavior in create_load_balancer mock
add CONTRIBUTORS, assign copyright
fix link in license
Fixing defect with handling of multiple <item> elements in reponse to describe-reservations