Add transports based on Azure PaaS (#891)

* Add transports based on Azure PaaS

This pull request adds two new transport implementations:

- `azurestoragequeues` is implemented on top of Azure Storage
  Queues [1]. This offers a simple but scalable and low-cost PaaS
  transport for Celery users in Azure. The transport is intended to be
  used in conjunction with the Azure Block Blob Storage backend [2].

- `azureservicebus` is implemented on top of Azure Service Bus [3] and
  offers PaaS support for more demanding Celery workloads in Azure. The
  transport is intended to be used in conjunction with the Azure
  CosmosDB backend [4].

This pull request was created together with @ankurokok, @dkisselev,
@evandropaula, @martinpeck and @michaelperel.

[1] https://azure.microsoft.com/en-us/services/storage/queues/
[2] https://github.com/celery/celery/pull/4685
[3] https://azure.microsoft.com/en-us/services/service-bus/
[4] https://github.com/celery/celery/pull/4720

* Exclude Azure transports from code coverage

There is test coverage for the transports but the tests require Azure
credentials to run (passed via environment variables) so codecov doesn't
exercise them.

* Remove env vars to configure transport

* Remove abbreviations

1 files changed, 2 insertions, 0 deletions

diff --git a/setup.py b/setup.py
index 77c35913..dac04d7e 100644
--- a/setup.py
+++ b/setup.py
@@ -130,6 +130,8 @@ setup(
         'librabbitmq': extras('librabbitmq.txt'),
         'pyro': extras('pyro.txt'),
         'slmq': extras('slmq.txt'),
+        'azurestoragequeues': extras('azurestoragequeues.txt'),
+        'azureservicebus': extras('azureservicebus.txt'),
         'qpid': extras('qpid.txt'),
         'consul': extras('consul.txt'),
     },