Consistent Logging Messages Across Resources

[hongil0316]

There's several places where we can improve logging across resources. This could be additional work on top of issue like this:

• Improve error handling for common/known errors #402
• Refactor Nuke Implementation for EC2 Resources.  #686 (comment)

Here are some suggestions:

• Repetitive logging we need to print out for all resources. We should be able to refactor so there's a single place to log things like this:

	if len(identifiers) == 0 {
		logging.Debugf("No API Gateways (v1) to nuke in region %s", gateway.Region)
	}

	if len(identifiers) > 100 {
		logging.Errorf("Nuking too many API Gateways (v1) at once (100): " +
			"halting to avoid hitting AWS API rate limiting")
		return TooManyApiGatewayErr{}
	}

consistent message format for users experience & readability:

• having consistent prefix.

	logging.Debugf("["+
			"OK] API Gateway (v1) %s deleted in %s", aws.StringValue(apigwID), gateway.Region)

	logging.Debugf(
		"[Failed] Error deleting API Gateway (v1) %s in %s", aws.StringValue(apigwID), gateway.Region)