We need `IServiceManagement`, however we don't use it directly. We need to use '[SubscriptionData.GetCurrentStorageAccount(IServiceManagement channel)](https://github.com/WindowsAzure/azure-sdk-tools/blob/dev/WindowsAzurePowershell/src/Management/Model/SubscriptionData.cs)' to get storage account from azure subscription and it take the `IServiceManagement` as the parameter.

Our `BlobClient` is a interface that could help us switch between the real azure storage client and mocked implementation, and it's hard to integrate with `Channel` object. So we want to use both `BlobClient` and `IServiceStorageManagement`.