Merge pull request #56 from yueluog/master

Merge pull request #56: Add UTC timestamp to gcimagebundle logging.
Changing DesiredAccounts._GetAttribute method to catch 404 HTTPError and raise all errors
Changing DesiredAccounts class to surface errors to the caller and handling errors at the top level. This helps us put a sleep in the while loop in case of errors to help prevent log spam.
Fixing typo in error code which I was using to test the changes and didn't actually meant to commit.
Minor changes
fix(google-daemon): use * for the passwd not !

useradd defaults to using ! as the "locked" password marker.
Unfortunatly, openssh interprets this to mean that it shouldn't let the
user in via ssh if PAM is missing. Work around this by using the *
marker which also means locked but is allowed by openssh.
Merge pull request #57 from HimanshuVasishth/master

Improving error handling and logging
feat(accounts): add users to the sudo group by default

On CoreOS the sudo group gets passwordless sudo. Add users to this
group.
Merge pull request #60 from coreos/add-sudo-group

feat(accounts): add users to the sudo group by default
Merge pull request #55 from coreos/master

fix(google-daemon): use * for the passwd not !
Use FQDN of metadata server name to retrieve metadata.