[AWS] add modify_vpc_attribute
[AWS] add modify_vpc_attribute
[vcloud_director] tests become pending not failing on absense of testable resources
Merge pull request #2388 from estonfer/modify_vpc_attribute

[AWS] Modify vpc attribute
Merge pull request #2389 from alphagov/vcloud_director_model_test_fixes

[vcloud_director] tests become pending on absence of testable resources
[rackspace] fixing broken tests caused by bad helper
Merge pull request #2393 from rackspace/test_fix7

[rackspace] fixing broken tests caused by bad helper