Looks like there is typo in the example code in README.md

```
	// Use log levels to set your log priority
	log2.SetLogLevel(DebugLevel)
```
Since this code is not in the logger package, it doesn't have access to `DebugLevel`.  Use this instead:
```
	// Use log levels to set your log priority
	log2.SetLogLevel(logger.DebugLevel)
```

Same for the WarningLevel 3 lines down.