Add zephyr mocks

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 88.59%. Comparing base (21816f4) to head (ab5f716). Report is 124 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #635 +/- ## ========================================== + Coverage 88.56% 88.59% +0.02% ========================================== Files 42 42 Lines 4565 4575 +10 ========================================== + Hits 4043 4053 +10 Misses 522 522 ```

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