Fix error when run with no arguments on Python 3

Python 3 changed the map built-in to return an iterable instead of a list.
When tested in a boolean context, this always returns True, even if it
would not return anything when iterated.

Instead of the usage being printed, this error was printed:
ERROR: 'Namespace' object has no attribute 'func'

Use list comprehension instead to ensure that an iterable isn't returned

Change-Id: Ie15f2fa8ee93ab26490e371133fa0f944430737b
Closes-bug: 1295356
Remove unused arguments to _boot()

reservation_id, min_count, max_count are never specified by any callers.
Remove the arguments and the code that checks the values.

Change-Id: I3794fd1eabbfb999c422c701af1ff64cd667313f
Merge "Fix error when run with no arguments on Python 3"
Merge "Remove unused arguments to _boot()"