Add a verbose flag for debugging

[frankcarey]

It's super handy to know what command is actually being run, especially when debugging commands. I'm using it locally and it looks like this. Especially useful when calling ahoy commands from another command like is shown here.

I think it would be good to implement with a -v flag. One thing I would add is the command that's actually called behind the scenes.

$ ahoy echo-test test
2015/12/01 19:23:22 run command:  ahoy echo-success "'quotes'" && ahoy echo-fail "'quotes'" && ahoy echo-maybe "'quotes'"
2015/12/01 19:23:22 run command:  echo "'quotes'"
'quotes'
2015/12/01 19:23:22 run command:  echo 'quotes'
quotes
2015/12/01 19:23:22 run command:  echo "'quotes'"
'quotes'

[frankcarey]

Fixed, there is now a --verbose flag you can set, or an $AHOY_VERBOSE environment variable you can use.