Rewrited mox tests to mock (part 1)

Preffered module for unittests is mock,
so, this commit is intended to remove mox module
from manila's dependencies in modules:
manila/tests/api/v1/test_shares.py
manila/tests/test_service.py
manila/tests/test_share_api.py
manila/tests/test_share_lvm.py
manila/tests/test_utils.py

Change-Id: Ie488b80dea0a1e66837c16d3e6ac8658a2045a2e
Partially implements: blueprint replace-mox-with-mock
Merge "Rewrited mox tests to mock (part 1)"