Supporting virtualbox
Merge branch 'master' of github.com:jcarley/mytechbooks

* 'master' of github.com:jcarley/mytechbooks:
  Removes if checks for bang! operations.
  Removes the temporary BookCreatedFailedError class.
  Used tap on the command result to get the result of running a command.
  Refactored the successful? method out of the controllers.  Adds command result object to encapsulate the result of running a command.
  Removes the command look in favor of directly passing in an instance of a command
  Refactored command bus to domain.  Adds elapsed time to profile command classes.