Added changes to cleanup storage account which created during server create flow and display warning
Merge pull request #134 from opscode/ameya-oc-11209-storage-account-cleanup

OC-11209: server create should not delete storage account in cleanup - unless created storage account
support to join domain for created VM.
add validations.
unit tests for domain join support.
more unit test for domain join.
more tests - negative test for missing domain options.
add support for user principal name (UPN) format (user@fully-qualified-DNS-domain) or the fully-qualified-DNS-domain\\username format.
remove debug logs.
add support to join domain in specific org unit using ldap dn.
test for domain user formats and MachineObjectOU option.
implement review comments.
Merge branch 'kd/OC-11120-domain' of https://github.com/opscode/knife-azure into kd/OC-11120-domain