provider/ec2: bootstrap fails with "failed to bootstrap environment: cannot start bootstrap instance: tagging root disk: timed out waiting for EBS volume to be associated"

[Andrew Wilkins]

See:
    http://reports.vapour.ws/releases/3124/job/aws-deploy-trusty-amd64-on-wily-amd64/attempt/220

I don't think there's much we can do apart from increasing the timeout. We're currently only waiting for 5 seconds, which evidently is not enough time for the root disk to be provisioned and attached to the instance.

Note, CI matches this to lp:1479546, which is wrong. They are separate issues; this one is specifically to do with tagging root disks, whereas the other one was about volume provisioning.