Adding a retry block when associating elastic IPs for nat instances
Agent should use new style blobstore properties
Added retry on unmounting image in stemcell builder
Updated external bootstrap tests for new subnets
Expect Resource NotFound to be raised when waiting for attachments
Fixing specs according to the new subnet setup
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  Fixing specs according to the new subnet setup
  Expect Resource NotFound to be raised when waiting for attachments
  Updated external bootstrap tests for new subnets
  Added retry on unmounting image in stemcell builder
  Agent should use new style blobstore properties
  Adding a retry block when associating elastic IPs for nat instances