Migration Plugin

It happens only via bindings, direct REST API calls work fine. To reproduce:

• migrate contnt with no storage path (e.g. errata, package group, etc)
• list pulp2content/ endpoint using bindings, observe error

Not sure if Ruby bindings are affected, Python ones definitely are.

Traceback (most recent call last):
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/IPython/core/interactiveshell.py", line 3343, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-1-8b97a68e577c>", line 1, in <module>
    cls.pulp2content_api.list()
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api/pulp2_content_api.py", line 78, in list
    return self.list_with_http_info(**kwargs)  # noqa: E501
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api/pulp2_content_api.py", line 226, in list_with_http_info
    collection_formats=collection_formats)
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api_client.py", line 370, in call_api
    _preload_content, _request_timeout, _host)
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api_client.py", line 209, in __call_api
    return_data = self.deserialize(response_data, response_type)
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api_client.py", line 281, in deserialize
    return self.__deserialize(data, response_type)
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api_client.py", line 320, in __deserialize
    return self.__deserialize_model(data, klass)
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api_client.py", line 659, in __deserialize_model
    kwargs[attr] = self.__deserialize(value, attr_type)
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api_client.py", line 298, in __deserialize
    for sub_data in data]
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api_client.py", line 298, in <listcomp>
    for sub_data in data]
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api_client.py", line 320, in __deserialize
    return self.__deserialize_model(data, klass)
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/api_client.py", line 661, in __deserialize_model
    instance = klass(**kwargs)
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/models/pulp2to3_migration_pulp2_content_response.py", line 84, in __init__
    self.pulp2_storage_path = pulp2_storage_path
  File "/usr/local/lib/pulp/lib64/python3.6/site-packages/pulpcore/client/pulp_2to3_migration/models/pulp2to3_migration_pulp2_content_response.py", line 229, in pulp2_storage_path
    raise ValueError("Invalid value for `pulp2_storage_path`, must not be `None`")  # noqa: E501
ValueError: Invalid value for `pulp2_storage_path`, must not be `None`