Migration Plugin

the pulp2repositories api does not contain the repository_href of the created repository. Its probably easy to add and would save us from having to look it up:

[#<Pulp2to3MigrationClient::Pulp2to3MigrationPulp2Repository:0x00007f05e4394518
  @is_migrated=true,
  @pulp2_object_id="5e29fb21b02e5354b9243ad3",
  @pulp2_repo_id="5b08c8a6-d3bb-41af-9cd4-cadf8fec2a55",
  @pulp3_distribution_hrefs="[\"/pulp/api/v3/distributions/file/file/e1fbefc4-bd25-42cb-a160-9b3b7a72eff4/\"]",
  @pulp3_publication_href="[\"/pulp/api/v3/publications/file/file/ecfc2157-2a3f-47d6-9835-6e89ba6c2f2b/\"]",
  @pulp3_remote_href="/pulp/api/v3/remotes/file/file/1634f526-1813-4ed0-b7cb-2769009359e5/",
  @pulp3_repository_version="/pulp/api/v3/repositories/file/file/b993a103-7835-46b6-b542-5521817c6613/versions/1/",
  @pulp_created=Thu, 23 Jan 2020 20:28:14 +0000,
  @pulp_href="/pulp/api/v3/pulp2repositories/ab6dad7f-b745-4573-8c3e-f2a6701d8de8/">]>

On an aside note, it appears not possible to find a repository_href from a repository_version, that may be a 2nd unrelated bug.