Enable verbose logging with --debug

[pradyunsg]

This helps ensure that all relevant context is presented when a failure happens and diagnosis is being done through the use of --debug.

[uranusjr]

Should we do even larger? I have no idea how many levels of verbosity we actually have…

[ichard26]

Setting verbosity to 2 should be enough as it enables the DEBUG logging level:

pip/src/pip/_internal/utils/logging.py

Lines 232 to 243 in af00870

	if verbosity >= 2:
	level_number = logging.DEBUG
	elif verbosity == 1:
	level_number = VERBOSE
	elif verbosity == -1:
	level_number = logging.WARNING
	elif verbosity == -2:
	level_number = logging.ERROR
	elif verbosity <= -3:
	level_number = logging.CRITICAL
	else:
	level_number = logging.INFO

This just needs a changelog entry, and it should be good to go!