Convert all prints to use loggers and appropriate log levels.

[dwf]

Specifically, stick something like

import logging
...
...

logger = logging.getLogger("put.module.name.here")

at the t op of the module.

Very verbose output with print statements should then be replaced with logger.debug(); less verbose but useful stuff with logger.info(); stuff that goes wrong that the user should know about even if they don't care about info() level stuff should be a logger.warning(), etc.

This will allow us to easily and programmatically redirect logging output, change logging verbosity, apply common styling to all log messages (add timestamps, blah).

See the Logging Cookbook and the logging module docs.

[memimo]

@dwf Wouldn't logging.getLogger(__name__) be better option than manually putting the module name?

[memimo]

Should we replace test files print statement as well?

[memimo]

Should we add a unit test to check for new PRs if they have exists print statement in the code? Although this would enforce it to test scripts as well.