Modify rally commands deployment, task, and verify

Small modifications to the rally commands 'deployment', 'task', and
'verify'.
In deployment, rename the subcommand endpoint to show, and remove
the pprint and json output options in subcommand config in favor of
pretty-printed json output only.
In task, perform the same in subcommand results as in config.
In verify, perform the same in subcommand results as in config.

Change-Id: I9686abf5088782e68111638da10be72c0e1135fa