extended IOPS support
Display number of instance store volumes per instance flavor.
[libvirt|compute] Allow volumes to have backing volumes
Merge pull request #2632 from 20goto10/feature/aws_rds_iops_values

AWS RDS - enhancements to IOPS support
Merge pull request #2636 from davissp14/master

Display number of instance store volumes per instance flavor.
Merge pull request #2633 from domcleal/libvirt-backing-volume

[libvirt|compute] Allow volumes to have backing volumes
Tests and fixes for Elasticache VPC subnet groups
Use endpoint, port, and path_style options in AWS storage Mock
add Iops to snapshot model
Merge pull request #2638 from sugarb/elasticache_create_cache_subnet_group

Tests and fixes for Elasticache VPC subnet groups
Merge pull request #2639 from cf-blobstore-eng/mock-path-style

Use endpoint, port, and path_style options in AWS storage Mock
Merge pull request #2641 from 20goto10/feature/aws_rds_iops_values

add Iops to snapshot model