Management command should lower log level pending verbosity

[ghost]

There's an informational logging message in the etag implementation: https://github.com/antonagestam/collectfast/blob/8bcdd77819d9c950bf4760ce6423da1a82cea579/collectfast/etag.py#L120

This is shown if collectstatic is run with verbosity 0 and should not be. This can be fixed in the management command by using logging.disable() if verbosity is zero.

[antonagestam]

Logging needs a major overhaul. The management command needs to somehow be setup so that loggers in other modules uses the management command logging facilities.