Update nuget packages to Azure Storage 4.3
No longer force AtomPub request formatting

* This was needed to work around a bug in an old version of OAData. The bug is now
  gone and instead this was throwing a MethodNotFound error because AtomPub was deprecated.
Merge pull request #90 from dontjee/updateToAzureStorageSDK4_3

Update to azure storage sdk 4.3