Microsoft Azure storage driver

An implementation of the storagedriver.StorageDriver interface which uses Microsoft Azure Blob Storage for object storage.

Parameters

Parameter	Required	Description
`accountname`	yes	Name of the Azure Storage Account.
`accountkey`	yes	Primary or Secondary Key for the Storage Account.
`container`	yes	Name of the Azure root storage container in which all registry data is stored. Must comply the storage container name requirements. For example, if your url is `https://myaccount.blob.core.windows.net/myblob` use the container value of `myblob`.
`realm`	no	Domain name suffix for the Storage Service API endpoint. For example realm for “Azure in China” would be `core.chinacloudapi.cn` and realm for “Azure Government” would be `core.usgovcloudapi.net`. By default, this is `core.windows.net`.
`copy_status_poll_max_retry`	no	Max retry number for polling of copy operation status. Retries use a simple backoff algorithm where each retry number is multiplied by `copy_status_poll_delay`, and this number is used as the delay. Set to -1 to disable retries and abort if the copy does not complete immediately. Defaults to 5.
`copy_status_poll_delay`	no	Time to wait between retries for polling of copy operation status. This time is multiplied by N on each retry, where N is the retry number. Defaults to 100ms