Require azure/core manually
'azure' moved part of it to a gem called 'azure_core'. They released a version that lists that gem as a dependency. When this version is used with 'fog-azure', we get an error because 'azure/core' isn't loaded (see https://github.com/Azure/azure-sdk-for-ruby/pull/383).
We can simply preload it in fog-azure and not let the error in the dependency affect us. We could also force the dependency to be a version before the split into 'azure' and 'azure_core'.
I think we'd need a new release after merging this change, as it stands right now fog-azure is broken (at least until https://github.com/Azure/azure-sdk-for-ruby/pull/383 is merged and a new release comes out)
@dLobatog Could you please re-verify whether we still need this fix as latest azure gem has been released and we have updated our dependency in fog-azure. Please let us know if you are still having issues? Thanks.