Add deployment check subcommand

* Check keystone endpoints and print user-friendly messages so the
user can easily troubleshoot issues,
* List all available services of your deployed OpenStack,
* Refactoring of benchmark.engine.bind in order to avoid redundancy.

Implements blueprint deployment-check-subcommand

Change-Id: Iecfc2e4c093f567b56c3990c598326942c50e34a