Added Support For Pending Storage Group Operations

[vontedduchaithra]

No description provided.

[coveralls]

coverage: 79.809% (-0.005%) from 79.814% — pendingstorage into master

[andy-maier]

I have two comments

1. On the commit message and PR title:

This PR does not "Add Support For Pending Storage Group Operations".

Instead, it:

• adds end2end tests for some functions
• adds mock support for some functions
• adds unit tests for some functions, using that mock support.

Please change the commit message accordingly. It should show the three items above, with details as to what operations are now mocked and what functions are now tested.

2. Since the new mock support is also available for users, a change log fragment file of type "feature" should be added that explains what is newly available, plus another one of type "feature" that briefly mentions the additional tests (you don't need to go into the details of which functions are tested as you do in the commit message, just mention the area at a high level (e.g. "Added end2end and unit testcases for FICON storage").