Introduces code coverage and expands the use of bandit to include
the shipyard_client. Triggers the run of bandit, coverage, and docs
to the base tox execution. Addresses several bandit issues by either
fixing or supplying # nosec to known "ok" uses of code that would
otherwise trigger a bandit error being reported.
This change also removes an artifact from refactoring (deckhand_client.py)
which moved to a subdirectory.
Change-Id: I47b4a6b945ade7ba42bc73a850848cd45c0b2390