Fixed few failing tests
Add module to docs, fix up module

Module `tests.robottelo.test_orm` is not part of the API documentation generated
by Sphinx. Add it to the API docs and fix documentation errors therein.
Add upload and delete manifest utility methods

These methods help manage an organization's subscription thought API by
allowing upload or delete a manifest.

Also add tests for paths and delete_manifest helper method. Other helper
methods should have their tests when the requests wrapper gets fixed.
Merge pull request #1256 from Ichimonji10/docs

Add module to docs, fix up module
Merge pull request #1249 from sghai/fix-tests

Fixed few failing tests
Merge pull request #1255 from elyezer/api-manifest-management

Add upload and delete manifest utility methods