Maintenance: Update logger to use timestamps

[quixoticmonk]

Summary

Add timestamp to the logging output across the eksupgrade codebase.

Why is this needed?

This would help in debugging issues related to timing like the initial delay in cluster status changing from ACTIVE to UPDATING to make decisions when to update nodegroups and addons.

Which area does this relate to?

Other

Solution

Create a logging utility which has a formatter attached to it.

logger = logging.getLogger(__name__)
handler = logging.StreamHandler()
formatter = logging.Formatter('%(asctime)s - %(levelname)s - %(message)s')
handler.setFormatter(formatter)
logger.addHandler(handler)