WIP: First version of inspect client.
Add tests for inspection client.
Rename the katcp object used in InspectClientAsync to katcp_client.
Renamed inspect_client to inspecting_client.
Fixed up some of the doc strings in inspecting_client.py .
Updates based on pull request comments.
Updates based on pull request comments.
Fixed remove sensor and updates based on pull request.
Added comments to class.
Clarify arguments in _difference() docstring
Merge pull request #32 from ska-sa/martin_inspect_client

Basic inspecting_client and tests