Pin Version of Azure Cosmos to <4 (apache#8956)

Old Repo: https://github.com/Azure/azure-cosmos-python
New Repo: https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/cosmos/azure-cosmos

azure-cosmos==4.0.0 was released on 20 May 2020 that breaks Airflow

(cherry picked from commit dd72040)

setup.py

@@ -225,7 +225,7 @@ def write_version(filename=os.path.join(*[my_dir, "airflow", "git_version"])):
     'azure-mgmt-containerinstance>=1.5.0'
 ]
 azure_cosmos = [
-    'azure-cosmos>=3.0.1'
+    'azure-cosmos>=3.0.1,<4',
 ]
 azure_data_lake = [
     'azure-datalake-store>=0.0.45'