Description of problem:
When trying to create an incremental update to a Content View (CV) version, applying some errata, it requires the environments to be listed where the version is, whereas there are cases where the CV version only lives in the Library or doesn't live in any Life Cycle Environment (LCE).

Version-Release number of selected component (if applicable):
6.1.7

How reproducible:
Always

Steps to Reproduce:
1. $ hammer content-view version incremental-update --content-view-version "xxx" --errata-ids yyy

Actual results:
The command fails.

Expected results:
The command succeeds and just applies the given errata(s) to the given CV version and creates a new CV minor version.

Additional info:

My use case:

LCEs are Library, Test, Prod
CV v1, v2 and v3 are in the Library (because CVa is never used directly, only through CCV)
CV v1 is used by CCV (Composite CV) in v10 promoted to Prod
CV v2 is used by CCV in v11 promoted to Test
CV v3 is used by CCV in v12 only published in Library
I want now to:
- add errata to CV v1, v2 and v3 generating v1.1, v2.1 and v3.1
- update CCV v10 to v1.1, CCV v11 to v2.1 and CCV v12 to v3.1 at a later stage
Note that CV might be used by other CCVs, but I don't think that's relevant here.