add yosemite to macOSXSeries
Prevent destroy-environment when desired.
Fixed error construction and format. Renamed vars for clarity and conformity.
Cleaned up error-related code based on review.
Made code readable
Merge branch 'master' into allocateaddress-maas
Initial skeleton of AllocateAddress for maas
Merge branch 'master' into allocateaddress-maas
Complete AllocateAddress first cut
Update comment
provider/ec2: allocate all instance stores

When starting an instance in EC2, specify all of the
instance stores in the block device mapping. The instance
started will have as many four attached, according to
the instance type.

getBlockDeviceMappings will be enhanced in the near
future to support attaching additional volumes to
instances at creation time (i.e. for charm storage).
Merge branch 'master' into allocateaddress-maas
use the metricsmanager runner
notification channel is a string so we know what was called
Update juju/utils in dependencies.tsv

Update to get ParseSize.
Environment variable manipulation is behind cmds for block/unblock operation.
Code readability improvement.
Merge branch 'master' of https://github.com/juju/juju into allocateaddress-maas
Renaming after switch from ListNetworks to Subnets
Return nil on success